Thrombosis

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Background: Despite the increased mortality rate of the novel coronavirus compared with influenza, little is understood about its pathogenicity. Prior studies have identified D-dimer levels, high Sequential Organ Failure Assessment score, and older age as markers for more severe disease and mortality. The specific cause of death of COVID-19 remains largely unknown.

This small case series piques interest in the potential underrecognized thromboembolic pathology of COVID-19. While not practice changing, this study highlights the importance of hospitalists staying attuned to further studies regarding VTE prophylaxis in COVID-19.

Bottom line: Autopsies of COVID-19 patients revealed a high incidence of thromboembolic events; COVID-19–induced coagulopathy may play an underrecognized role in pathogenesis.

Citation: Wichmann D et al. Autopsy findings and venous thromboembolism in patients with COVID-19. Ann Intern Med. 2020;173(4):268-77.

Dr. Fletcher is a hospitalist at the Lexington (Ky.) VA Health Care System.

Background: Despite the increased mortality rate of the novel coronavirus compared with influenza, little is understood about its pathogenicity. Prior studies have identified D-dimer levels, high Sequential Organ Failure Assessment score, and older age as markers for more severe disease and mortality. The specific cause of death of COVID-19 remains largely unknown.

This small case series piques interest in the potential underrecognized thromboembolic pathology of COVID-19. While not practice changing, this study highlights the importance of hospitalists staying attuned to further studies regarding VTE prophylaxis in COVID-19.

Bottom line: Autopsies of COVID-19 patients revealed a high incidence of thromboembolic events; COVID-19–induced coagulopathy may play an underrecognized role in pathogenesis.

Citation: Wichmann D et al. Autopsy findings and venous thromboembolism in patients with COVID-19. Ann Intern Med. 2020;173(4):268-77.

Dr. Fletcher is a hospitalist at the Lexington (Ky.) VA Health Care System.

Background: Despite the increased mortality rate of the novel coronavirus compared with influenza, little is understood about its pathogenicity. Prior studies have identified D-dimer levels, high Sequential Organ Failure Assessment score, and older age as markers for more severe disease and mortality. The specific cause of death of COVID-19 remains largely unknown.

This small case series piques interest in the potential underrecognized thromboembolic pathology of COVID-19. While not practice changing, this study highlights the importance of hospitalists staying attuned to further studies regarding VTE prophylaxis in COVID-19.

Bottom line: Autopsies of COVID-19 patients revealed a high incidence of thromboembolic events; COVID-19–induced coagulopathy may play an underrecognized role in pathogenesis.

Citation: Wichmann D et al. Autopsy findings and venous thromboembolism in patients with COVID-19. Ann Intern Med. 2020;173(4):268-77.

Dr. Fletcher is a hospitalist at the Lexington (Ky.) VA Health Care System.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

Circulating ketone bodies (KBs) are substantially elevated at presentation and 24 hours after ST-segment elevation myocardial infarction (STEMI), according to new research.

The study also showed that greater KB levels measured after 24 hours of reperfusion were associated with larger infarct size and reduced left ventricular ejection fraction (LVEF).

The findings suggest a potential role for ketone metabolism in response to myocardial ischemia, conclude researchers in their report, published in the October 5 issue of the Journal of the American College of Cardiology.

“Ketones serve as an alternative source of energy for the heart,” lead author Marie-Sophie L.Y. de Koning, MD, University Medical Center Groningen, the Netherlands, told this news organization.

“These results might suggest that ketone bodies may be an important fuel for the heart after myocardial ischemia.” The role of KBs in heart failure has been previously studied, but their role in myocardial infarction has not, Dr. De Koning said.

“In heart failure, metabolic changes occur that cause the heart to increasingly rely on ketone bodies as an important energy source. Accordingly, concentrations of circulating ketone bodies are elevated and higher concentrations have been linked with more severe heart failure,” she said.

”This might suggest that upregulation of ketone metabolism is a universal cardiac response to stress,” Dr. De Koning added. “But the role of ketone bodies in myocardial infarction remained largely unknown, and this triggered us to investigate circulating ketone bodies in patients presenting with STEMI.”

She and her team measured circulating KBs in archived plasma samples from 369 participants in the randomized GIPS-III trial. The study had primarily looked at the effect of 4 months of metformin therapy, compared with placebo, on LVEF in nondiabetic patients with a first STEMI.

Blood samples had been taken at baseline before percutaneous coronary intervention (PCI), at 24 hours after reperfusion, and at 4 months.

The current study investigated longitudinal post-STEMI changes in the circulating KBs beta-hydroxybutyrate, acetoacetate, and acetone. It also looked at associations of KBs with infarct size and LVEF, both of which were measured with cardiac magnetic resonance (CMR) imaging 4 months after STEMI.

Circulating KB levels were three times higher at STEMI presentation than at 4 months. At presentation, the median total KB level was 520 μmol/L. It was still higher 24 hours after reperfusion than at 4 months (206 vs. 166 μmol/L; P < .001).

The 24-hour KB elevations were independently and positively associated with larger infarct size (P = .016) and lower LVEF (P = .012), the group reports.

“Our results indicate a possible role for ketone bodies during myocardial infarction,” Dr. De Koning said.

The KB elevations were probably followed by “an increase in cardiac ketone body metabolism, in order to fuel the heart that is energetically depleted.”

But the study didn’t explore cardiac KB consumption, Dr. De Koning cautioned, adding that the next steps in this research should be to investigate post-STEMI cardiac ketone metabolism and its pathophysiologic mechanisms. “This may facilitate future trials to study therapeutic effects of ketone body supplementation during or after STEMI.”

The current findings “form an essential basis for our understanding of the role of KBs in ischemia/reperfusion,” write Salva R. Yurista, MD, PhD, and colleagues, Massachusetts General Hospital and Harvard Medical School, Boston, in an accompanying editorial.

“Although the appeal of enhancing KBs as a therapeutic approach is understandable, additional rigorous preclinical and clinical studies will be required to test this therapeutic hypothesis and determine the mechanisms contributing to any benefits observed,” they note.

”Exposure to cardiac stress, such as ischemia, infarction, or heart failure, will stimulate the release of neurohormones, pro-inflammatory cytokines, and natriuretic peptides, which may play roles in stimulating ketogenesis or the production of ketone bodies,” Dr. Yurista told this news organization.

The increased circulating ketone concentrations and myocardial ketone oxidation that were associated with poor functional outcomes have been reported in other clinical contexts, including heart failure with reduced ejection fraction, heart failure with preserved cardiac function, diabetic cardiomyopathy, and arrhythmogenic cardiomyopathy, he said.

Dr. Yurista agrees that KBs could have therapeutic merit.

“Circulating ketone concentrations determine the contribution of ketones to the cardiac diet,” he said. “Thus, increasing cardiac delivery of ketone bodies through supplementation or other means to the heart undergoing stress, including STEMI and heart failure, could have therapeutic potential.”

The GIPS-III trial was supported by the Netherlands Organization for Health Research and Development (ZonMw). Neither Dr. De Koning nor the other authors report relevant financial relationships. Dr. Yurista and the other editorialists report no relevant relationships.

A version of this article first appeared on Medscape.com.

Circulating ketone bodies (KBs) are substantially elevated at presentation and 24 hours after ST-segment elevation myocardial infarction (STEMI), according to new research.

The study also showed that greater KB levels measured after 24 hours of reperfusion were associated with larger infarct size and reduced left ventricular ejection fraction (LVEF).

The findings suggest a potential role for ketone metabolism in response to myocardial ischemia, conclude researchers in their report, published in the October 5 issue of the Journal of the American College of Cardiology.

“Ketones serve as an alternative source of energy for the heart,” lead author Marie-Sophie L.Y. de Koning, MD, University Medical Center Groningen, the Netherlands, told this news organization.

“These results might suggest that ketone bodies may be an important fuel for the heart after myocardial ischemia.” The role of KBs in heart failure has been previously studied, but their role in myocardial infarction has not, Dr. De Koning said.

“In heart failure, metabolic changes occur that cause the heart to increasingly rely on ketone bodies as an important energy source. Accordingly, concentrations of circulating ketone bodies are elevated and higher concentrations have been linked with more severe heart failure,” she said.

”This might suggest that upregulation of ketone metabolism is a universal cardiac response to stress,” Dr. De Koning added. “But the role of ketone bodies in myocardial infarction remained largely unknown, and this triggered us to investigate circulating ketone bodies in patients presenting with STEMI.”

She and her team measured circulating KBs in archived plasma samples from 369 participants in the randomized GIPS-III trial. The study had primarily looked at the effect of 4 months of metformin therapy, compared with placebo, on LVEF in nondiabetic patients with a first STEMI.

Blood samples had been taken at baseline before percutaneous coronary intervention (PCI), at 24 hours after reperfusion, and at 4 months.

The current study investigated longitudinal post-STEMI changes in the circulating KBs beta-hydroxybutyrate, acetoacetate, and acetone. It also looked at associations of KBs with infarct size and LVEF, both of which were measured with cardiac magnetic resonance (CMR) imaging 4 months after STEMI.

Circulating KB levels were three times higher at STEMI presentation than at 4 months. At presentation, the median total KB level was 520 μmol/L. It was still higher 24 hours after reperfusion than at 4 months (206 vs. 166 μmol/L; P < .001).

The 24-hour KB elevations were independently and positively associated with larger infarct size (P = .016) and lower LVEF (P = .012), the group reports.

“Our results indicate a possible role for ketone bodies during myocardial infarction,” Dr. De Koning said.

The KB elevations were probably followed by “an increase in cardiac ketone body metabolism, in order to fuel the heart that is energetically depleted.”

But the study didn’t explore cardiac KB consumption, Dr. De Koning cautioned, adding that the next steps in this research should be to investigate post-STEMI cardiac ketone metabolism and its pathophysiologic mechanisms. “This may facilitate future trials to study therapeutic effects of ketone body supplementation during or after STEMI.”

The current findings “form an essential basis for our understanding of the role of KBs in ischemia/reperfusion,” write Salva R. Yurista, MD, PhD, and colleagues, Massachusetts General Hospital and Harvard Medical School, Boston, in an accompanying editorial.

“Although the appeal of enhancing KBs as a therapeutic approach is understandable, additional rigorous preclinical and clinical studies will be required to test this therapeutic hypothesis and determine the mechanisms contributing to any benefits observed,” they note.

”Exposure to cardiac stress, such as ischemia, infarction, or heart failure, will stimulate the release of neurohormones, pro-inflammatory cytokines, and natriuretic peptides, which may play roles in stimulating ketogenesis or the production of ketone bodies,” Dr. Yurista told this news organization.

The increased circulating ketone concentrations and myocardial ketone oxidation that were associated with poor functional outcomes have been reported in other clinical contexts, including heart failure with reduced ejection fraction, heart failure with preserved cardiac function, diabetic cardiomyopathy, and arrhythmogenic cardiomyopathy, he said.

Dr. Yurista agrees that KBs could have therapeutic merit.

“Circulating ketone concentrations determine the contribution of ketones to the cardiac diet,” he said. “Thus, increasing cardiac delivery of ketone bodies through supplementation or other means to the heart undergoing stress, including STEMI and heart failure, could have therapeutic potential.”

The GIPS-III trial was supported by the Netherlands Organization for Health Research and Development (ZonMw). Neither Dr. De Koning nor the other authors report relevant financial relationships. Dr. Yurista and the other editorialists report no relevant relationships.

A version of this article first appeared on Medscape.com.

Circulating ketone bodies (KBs) are substantially elevated at presentation and 24 hours after ST-segment elevation myocardial infarction (STEMI), according to new research.

The study also showed that greater KB levels measured after 24 hours of reperfusion were associated with larger infarct size and reduced left ventricular ejection fraction (LVEF).

The findings suggest a potential role for ketone metabolism in response to myocardial ischemia, conclude researchers in their report, published in the October 5 issue of the Journal of the American College of Cardiology.

“Ketones serve as an alternative source of energy for the heart,” lead author Marie-Sophie L.Y. de Koning, MD, University Medical Center Groningen, the Netherlands, told this news organization.

“These results might suggest that ketone bodies may be an important fuel for the heart after myocardial ischemia.” The role of KBs in heart failure has been previously studied, but their role in myocardial infarction has not, Dr. De Koning said.

“In heart failure, metabolic changes occur that cause the heart to increasingly rely on ketone bodies as an important energy source. Accordingly, concentrations of circulating ketone bodies are elevated and higher concentrations have been linked with more severe heart failure,” she said.

”This might suggest that upregulation of ketone metabolism is a universal cardiac response to stress,” Dr. De Koning added. “But the role of ketone bodies in myocardial infarction remained largely unknown, and this triggered us to investigate circulating ketone bodies in patients presenting with STEMI.”

She and her team measured circulating KBs in archived plasma samples from 369 participants in the randomized GIPS-III trial. The study had primarily looked at the effect of 4 months of metformin therapy, compared with placebo, on LVEF in nondiabetic patients with a first STEMI.

Blood samples had been taken at baseline before percutaneous coronary intervention (PCI), at 24 hours after reperfusion, and at 4 months.

The current study investigated longitudinal post-STEMI changes in the circulating KBs beta-hydroxybutyrate, acetoacetate, and acetone. It also looked at associations of KBs with infarct size and LVEF, both of which were measured with cardiac magnetic resonance (CMR) imaging 4 months after STEMI.

Circulating KB levels were three times higher at STEMI presentation than at 4 months. At presentation, the median total KB level was 520 μmol/L. It was still higher 24 hours after reperfusion than at 4 months (206 vs. 166 μmol/L; P < .001).

The 24-hour KB elevations were independently and positively associated with larger infarct size (P = .016) and lower LVEF (P = .012), the group reports.

“Our results indicate a possible role for ketone bodies during myocardial infarction,” Dr. De Koning said.

The KB elevations were probably followed by “an increase in cardiac ketone body metabolism, in order to fuel the heart that is energetically depleted.”

But the study didn’t explore cardiac KB consumption, Dr. De Koning cautioned, adding that the next steps in this research should be to investigate post-STEMI cardiac ketone metabolism and its pathophysiologic mechanisms. “This may facilitate future trials to study therapeutic effects of ketone body supplementation during or after STEMI.”

The current findings “form an essential basis for our understanding of the role of KBs in ischemia/reperfusion,” write Salva R. Yurista, MD, PhD, and colleagues, Massachusetts General Hospital and Harvard Medical School, Boston, in an accompanying editorial.

“Although the appeal of enhancing KBs as a therapeutic approach is understandable, additional rigorous preclinical and clinical studies will be required to test this therapeutic hypothesis and determine the mechanisms contributing to any benefits observed,” they note.

”Exposure to cardiac stress, such as ischemia, infarction, or heart failure, will stimulate the release of neurohormones, pro-inflammatory cytokines, and natriuretic peptides, which may play roles in stimulating ketogenesis or the production of ketone bodies,” Dr. Yurista told this news organization.

The increased circulating ketone concentrations and myocardial ketone oxidation that were associated with poor functional outcomes have been reported in other clinical contexts, including heart failure with reduced ejection fraction, heart failure with preserved cardiac function, diabetic cardiomyopathy, and arrhythmogenic cardiomyopathy, he said.

Dr. Yurista agrees that KBs could have therapeutic merit.

“Circulating ketone concentrations determine the contribution of ketones to the cardiac diet,” he said. “Thus, increasing cardiac delivery of ketone bodies through supplementation or other means to the heart undergoing stress, including STEMI and heart failure, could have therapeutic potential.”

The GIPS-III trial was supported by the Netherlands Organization for Health Research and Development (ZonMw). Neither Dr. De Koning nor the other authors report relevant financial relationships. Dr. Yurista and the other editorialists report no relevant relationships.

A version of this article first appeared on Medscape.com.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

A new series of cases of cerebral venous sinus thrombosis (CVST) linked to the adenoviral vector COVID-19 vaccines has been reported, confirming the severity of the reaction and the associated high mortality rate.

The new series comes from an international registry of consecutive patients who experienced CVST within 28 days of COVID-19 vaccination between March 29 and June 18, 2021, from 81 hospitals in 19 countries.

The cases are described in an article published online on Sept. 28. in JAMA Neurology.

“This is a reliable description on the clinical condition of these patients with CVST associated with COVID-19 vaccination. It is striking that this a much worse condition than CVST not associated with COVID-19 vaccination, with a much higher rate of intracerebral hemorrhage and coma and a much higher mortality rate,” senior author Jonathan M. Coutinho, MD, Amsterdam University Medical Centers, told this news organization.

These data confirm the observations from an earlier U.K. cohort in which cases of cerebral venous thrombosis linked to COVID-19 vaccination occurred.

“This is the biggest series, and as an international series, it gives a broader perspective from a larger range of countries,” Dr. Coutinho said. “All the data together show that, although this side effect is rare, the consequences are very severe,” he added.

In the current study, the researchers regarded CVST as being linked to the vaccine if it was accompanied by thrombosis with thrombocytopenia syndrome (TTS), as evidenced by thrombosis and new-onset thrombocytopenia.

In the cohort of 116 patients with CVST after COVID-19 vaccination, 78 (67.2%) had thrombosis with TTS and were thus classified as having had a vaccine-related adverse event. These patients were frequently comatose at presentation (24%) and often had intracerebral hemorrhage (68%) and concomitant thromboembolism (36%); 47% died during hospitalization.

These patients were compared with the 38 patients in the same cohort who had CVST but in whom there was no indication of concomitant thrombosis and thrombocytopenia. The case patients were also compared with a control group of 207 patients with CVST who were included in a separate international registry before the COVID-19 pandemic.

Mortality rates were much higher among the patients deemed to have had a vaccine-related CVST. The in-hospital mortality rate was 47%, compared with 5% among the patients in the same cohort who did not have TTS and 3.9% among the prepandemic control group.

The mortality rate was even higher (61%) among patients in the TTS group for whom the diagnosis was made before the condition garnered attention in the scientific community. The mortality rate was 42% among patients diagnosed later.

Of the 78 patients in whom CVST and TTS occurred after COVID-19 vaccination in this cohort, 76 had received the AstraZeneca vaccine (in 75 patients, CVST and TTS occurred after the first vaccination; in one patient, they occurred after the second vaccination). One patient had received the Johnson & Johnson vaccine, and one had received the Pfizer vaccine.

“After more analysis, the case after the Pfizer vaccination is not believed to be caused by the vaccine,” Dr. Coutinho said. “In that case, the patient had a platelet count just below the lower limit and was taking an immunomodulator drug that is known to be associated with thrombocytopenia.”

For two patients who received the AstraZeneca vaccine, there was also an alternative explanation for the thrombocytopenia.

Dr. Coutinho also pointed out that the Johnson & Johnson vaccine has been used mainly in the United States, and these data were largely from other countries.

The median time from vaccination to CVST symptom onset was 9 days in the TTS group. The median platelet count at hospital admission among patients with postvaccination CVST-TTS was 45. Three patients presented with a normal platelet count and developed thrombocytopenia during admission; two patients presented with mild thrombocytopenia, 30 presented with moderate thrombocytopenia, and 43 presented with severe thrombocytopenia.

Antibodies against platelet factor 4 (PF4) were measured in 69 patients with TTS, of whom 63 (91%) tested positive (the one patient in whom TTS occurred after the patient received the Pfizer vaccine did not test positive). However, the researchers note that sensitivity varies among different PF4 ELISA tests. Findings of platelet activation assays were positive in all 36 tested patients.

In the TTS group, 52 patients (67%) received immunomodulation therapy, most often intravenous immunoglobulins (IVIG). Among patients treated with IVIG, the mortality rate was lower (28%).
 

Different from CVST linked to natural COVID-19 infection

Dr. Coutinho noted that CVST can occur in natural SARS-CoV-2 infection but that vaccine-associated CVST is very different.

“In natural COVID-19 infection, there is an increased risk of thrombosis, and some patients can get CVST as a part of this, but in these cases, this is not accompanied by thrombocytopenia. While the CVST in natural COVID-19 infection is also associated with a bad prognosis, this is more to do with the underlying disease. It is normally the very sick COVID patients who develop CVST, and these patients usually die from the underlying disease rather than the CVST itself,” he explained.

“Clinicians need to be aware of vaccine-related CVST, as it requires very specific and rapid treatment,” Dr. Coutinho stressed.

“Patients presenting with an extremely severe headache (unlike any headache they’ve had before) or with seizures or a focal deficit (weakness in arm or problems with speaking or vision) within 4 weeks of an adenovirus COVID-19 vaccination should ring alarm bells. It is important to do diagnostics quickly, with a platelet count the most important first step, and a rapid CT/MRI scan,” he said.

Other tests that should be conducted are D-dimer for thrombosis and the PF4 antibody test. But results for the PF4 antibody test can take days to come back, and clinicians shouldn’t wait for that, Dr. Coutinho notes.

“Specific treatment needs to be given immediately – with anticoagulation (preferably nonheparin) and immunomodulation with IVIG to stop the immune reaction. Platelets should not be given – that may seem counterintuitive in patients with a low platelet count, but giving platelets makes it worse,” he said.
 

Is there a geographic difference?

Dr. Coutinho pointed out that fewer cases of this vaccine-related CVST are being reported at the current time.

“We are not sure why this is the case. These adenovirus vaccines are not being used much now in Western countries, but our collaboration covers many less developed countries in South America and Asia, which are relying heavily on these vaccines. We are now shifting focus to these countries, but so far we have only seen a handful of cases from these areas,” he said.

He suggested that this may be because these countries started their vaccination programs later and are vaccinating their elderly (who are not so susceptible to this side effect) first, or it may be because of some environmental or genetic factor that has not yet been discovered.

“This is now an important research question – is the risk of vaccine-induced CVST the same in different countries or ethnicities? This could influence decisions on future vaccine strategies,” Dr. Coutinho said.

“So far, female sex is the strongest risk factor for vaccine-induced CVST. In our cohort, 81% of cases were in women. In addition, 95% were White, but that doesn’t allow us to conclude that this is a risk factor, as the majority of people who have been vaccinated are White. So, we have no clear insight into that yet,” he said.

In a comment for this news organization, the lead author of the previous U.K. report of a series of 70 cases of cerebral venous thrombosis linked to COVID-19 vaccination, Richard Perry, PhD, University College Hospital, London, described this new report as “an excellent study, with many of the same strengths and weaknesses as our study and has very similar results.”

Dr. Perry noted that the two studies used slightly different definitions of vaccine-induced thrombotic thrombocytopenia, but the cases reported appear to be very similar overall. “It is reassuring and gratifying to see that they have made such similar observations,” he said.

“And as they have drawn their cases from a broad range of countries whereas ours were all from the U.K., this provides evidence that the observations from both studies are reasonably generalizable,” he added.

Dr. Perry pointed out that this new report states that TTS occurred in one patient after the patient had received a second dose of the AstraZeneca vaccine. “I would like to know more about this case, because we didn’t see any cases after a second dose in our cohort,” he said.

Dr. Coutinho responded that he didn’t believe this was the first reported case after the second dose.

The study did not receive any specific funding. Dr. Coutinho has received grants paid to his institution from Boehringer Ingelheim and Bayer and payments paid to his institution for data safety monitoring board participation by Bayer.

A version of this article first appeared on Medscape.com.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

Treatment with acetylsalicylic acid (ASA) or heparin is associated with an increased risk for symptomatic intracranial hemorrhage (sICH) in patients with ischemic stroke who are undergoing endovascular therapy (EVT), new data show.

In this population, ASA and heparin are each associated with an approximately doubled risk for sICH when administered during EVT.

“We did not find any evidence for a beneficial effect on functional outcome,” investigator Wouter van der Steen, MD, research physician and PhD student at Erasmus University Medical Center, Rotterdam, the Netherlands, told this news organization. The possibility that a positive effect would be observed if the trial were continued was considered negligible, he added.

The researchers stopped the trial for safety reasons and recommend avoiding the evaluated dosages of both medications during EVT for ischemic stroke, said Dr. van der Steen.

He presented the findings from the MR CLEAN-MED trial at the European Stroke Organisation Conference (ESOC) 2021, which was held online.
 

Trial stopped for safety

Previous research has supported the safety and efficacy of EVT for ischemic stroke. Still, more than 30% of patients do not recover, despite fast and complete recanalization. Incomplete microvascular reperfusion (IMR) could explain this incomplete recovery, the researchers note.

Microthrombi, which occlude distal vessels, and neutrophil extracellular traps can cause IMR. This problem can be reduced through treatment with ASA, which has an antithrombotic effect, or with heparin, which dissolves neutrophil extracellular traps, they add. Although these drugs are associated with good clinical outcomes, they entail an increased risk for sICH.

The investigators conducted the multicenter, randomized controlled MR CLEAN-MED trial to evaluate the effect of intravenous (IV) ASA and heparin, alone or in combination, during EVT for acute ischemic stroke. Treatment was open label, but outcome assessment was blinded. Eligible participants were adults with a National Institutes of Health Stroke Scale (NIHSS) score of greater than or equal to 2 and an anterior circulation large-vessel occlusion for whom EVT could be initiated in fewer than 6 hours.

Investigators randomly assigned patients to receive or not to receive ASA. Within each of these two treatment groups, patients were randomly assigned to receive no heparin, low-dose heparin, or moderate-dose heparin.

ASA was given in a loading dose of 300 mg. Patients who were given low-dose heparin received a loading dose of 5,000 IU followed by 500 IU/h for 6 hours. Patients who received moderate-dose heparin were given a loading dose of 5,000 IU followed by 1,250 IU/h for 6 hours.

The study’s primary outcome was Modified Rankin Scale (mRS) score at 90 days. Secondary outcomes were NIHSS score at 24 hours, NIHSS score at 5 to 7 days, and recanalization grade at 24 hours on CT angiography or MRI. The primary safety outcomes were sICH and death within 90 days.

An independent, unblinded data and safety monitoring board (DSMB) assessed the risk for the primary safety outcomes throughout the trial. The board performed interim analyses of safety and efficacy for every 300 patients.

After the fourth safety assessment, the DSMB recommended that enrollment in the moderate-dose heparin arm be discontinued for safety reasons. Enrollment in other arms continued.

After the second interim analysis, the DSMB advised that the trial steering committee be unblinded to decide whether to stop or continue the trial. The steering committee decided to stop the trial for reasons of safety.
 

Increased risk for sICH

In all, 628 patients were included in the study. The ASA groups included 310 patients, and the no-ASA groups included 318 patients. In all, 332 participants received heparin, and 296 received no heparin.

The demographic characteristics were well balanced between groups. The population’s median age was 73 years, and about 53% were men. The median baseline NIHSS score was approximately 15. About 74% of patients received IV thrombolysis. The median baseline Alberta Stroke Program Early CT Scan score was 9.

The investigators observed a slight shift toward worse outcome in the ASA group, compared with the no-ASA group (adjusted OR, 0.91). In addition, the ASA group had a significantly increased risk for sICH, compared with the no-ASA group (14% vs. 7.2%; aOR, 1.95).

Patients in the ASA group were less likely to have good functional outcome (mRS of 0 to 2; aOR, 0.76), and the mortality rate tended to be higher.

The researchers found a nonsignificant shift toward a worse functional outcome in the heparin group, compared with the no-heparin group (aOR, 0.81). The risk for sICH was significantly higher in the heparin group, compared with the no-heparin group (13% vs. 7.4%; aOR, 2.00).

Patients in the heparin group were also less likely to have a good functional outcome (aOR, 0.78), and there was a nonsignificant increase in risk for death among those patients.

The rate of sICH was 11% in the group that received low-dose heparin; it was 26% in the group that received moderate-dose heparin (aOR, 6.05). The mortality rate was 23% in the low-dose group and 47% in the moderate-dose group (aOR, 5.45).

There was no significant interaction between ASA and heparin on the primary outcome and on sICH occurrence.
 

‘A unique trial’

“MR CLEAN-MED is a unique trial because it investigated a widely used treatment but until now without any proof of effectiveness,” said Dr. van der Steen. The researchers expect that their findings will have a strong impact on the management of patients with acute ischemic stroke. They suggest that the administration of antithrombotic agents during EVT be avoided.

“We consider it probable that the increased risk of sICH explains at least a part of the nonsignificant shift towards a worse functional outcome,” co-investigator Bob Roozenbeek, MD, PhD, a neurologist at the Erasmus Medical Center, said in an interview. “However, to make more definite statements, we will have to do more in-depth analyses.”

It remains unclear whether the periprocedural use of lower dosages of antithrombotic agents or of a single bolus of heparin could be safe and effective, said Dr. van der Steen.

To gain insight into these questions, the investigators will evaluate the effect of the medications and dosages examined in this trial on primary hemostasis and coagulation activity in the trial population. They also plan to examine the effect of primary hemostasis and coagulation activity on risk for sICH and functional outcome.

Enhancing the effectiveness of thrombectomy for acute ischemic stroke continues to be an important goal for stroke therapy, said Mark Fisher, MD, professor of neurology and pathology and laboratory medicine at the University of California, Irvine, who commented on the findings for this news organization.

At least three strategies are available: The use of ancillary antithrombotic medications, neuroprotection, and modulation of the vasoconstrictive properties of the microcirculation.

“Results of MR CLEAN-MED argue against the antithrombotic strategy,” said Dr. Fisher. “The alternate strategies remain viable, and results of interventions using those approaches are awaited with great interest.”

The study was funded by the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative and the Brain Foundation Netherlands. Funding also was provided by Stryker, Medtronic, and Cerenovus. Dr. van der Steen and Dr. Fisher have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Treatment with acetylsalicylic acid (ASA) or heparin is associated with an increased risk for symptomatic intracranial hemorrhage (sICH) in patients with ischemic stroke who are undergoing endovascular therapy (EVT), new data show.

In this population, ASA and heparin are each associated with an approximately doubled risk for sICH when administered during EVT.

“We did not find any evidence for a beneficial effect on functional outcome,” investigator Wouter van der Steen, MD, research physician and PhD student at Erasmus University Medical Center, Rotterdam, the Netherlands, told this news organization. The possibility that a positive effect would be observed if the trial were continued was considered negligible, he added.

The researchers stopped the trial for safety reasons and recommend avoiding the evaluated dosages of both medications during EVT for ischemic stroke, said Dr. van der Steen.

He presented the findings from the MR CLEAN-MED trial at the European Stroke Organisation Conference (ESOC) 2021, which was held online.
 

Trial stopped for safety

Previous research has supported the safety and efficacy of EVT for ischemic stroke. Still, more than 30% of patients do not recover, despite fast and complete recanalization. Incomplete microvascular reperfusion (IMR) could explain this incomplete recovery, the researchers note.

Microthrombi, which occlude distal vessels, and neutrophil extracellular traps can cause IMR. This problem can be reduced through treatment with ASA, which has an antithrombotic effect, or with heparin, which dissolves neutrophil extracellular traps, they add. Although these drugs are associated with good clinical outcomes, they entail an increased risk for sICH.

The investigators conducted the multicenter, randomized controlled MR CLEAN-MED trial to evaluate the effect of intravenous (IV) ASA and heparin, alone or in combination, during EVT for acute ischemic stroke. Treatment was open label, but outcome assessment was blinded. Eligible participants were adults with a National Institutes of Health Stroke Scale (NIHSS) score of greater than or equal to 2 and an anterior circulation large-vessel occlusion for whom EVT could be initiated in fewer than 6 hours.

Investigators randomly assigned patients to receive or not to receive ASA. Within each of these two treatment groups, patients were randomly assigned to receive no heparin, low-dose heparin, or moderate-dose heparin.

ASA was given in a loading dose of 300 mg. Patients who were given low-dose heparin received a loading dose of 5,000 IU followed by 500 IU/h for 6 hours. Patients who received moderate-dose heparin were given a loading dose of 5,000 IU followed by 1,250 IU/h for 6 hours.

The study’s primary outcome was Modified Rankin Scale (mRS) score at 90 days. Secondary outcomes were NIHSS score at 24 hours, NIHSS score at 5 to 7 days, and recanalization grade at 24 hours on CT angiography or MRI. The primary safety outcomes were sICH and death within 90 days.

An independent, unblinded data and safety monitoring board (DSMB) assessed the risk for the primary safety outcomes throughout the trial. The board performed interim analyses of safety and efficacy for every 300 patients.

After the fourth safety assessment, the DSMB recommended that enrollment in the moderate-dose heparin arm be discontinued for safety reasons. Enrollment in other arms continued.

After the second interim analysis, the DSMB advised that the trial steering committee be unblinded to decide whether to stop or continue the trial. The steering committee decided to stop the trial for reasons of safety.
 

Increased risk for sICH

In all, 628 patients were included in the study. The ASA groups included 310 patients, and the no-ASA groups included 318 patients. In all, 332 participants received heparin, and 296 received no heparin.

The demographic characteristics were well balanced between groups. The population’s median age was 73 years, and about 53% were men. The median baseline NIHSS score was approximately 15. About 74% of patients received IV thrombolysis. The median baseline Alberta Stroke Program Early CT Scan score was 9.

The investigators observed a slight shift toward worse outcome in the ASA group, compared with the no-ASA group (adjusted OR, 0.91). In addition, the ASA group had a significantly increased risk for sICH, compared with the no-ASA group (14% vs. 7.2%; aOR, 1.95).

Patients in the ASA group were less likely to have good functional outcome (mRS of 0 to 2; aOR, 0.76), and the mortality rate tended to be higher.

The researchers found a nonsignificant shift toward a worse functional outcome in the heparin group, compared with the no-heparin group (aOR, 0.81). The risk for sICH was significantly higher in the heparin group, compared with the no-heparin group (13% vs. 7.4%; aOR, 2.00).

Patients in the heparin group were also less likely to have a good functional outcome (aOR, 0.78), and there was a nonsignificant increase in risk for death among those patients.

The rate of sICH was 11% in the group that received low-dose heparin; it was 26% in the group that received moderate-dose heparin (aOR, 6.05). The mortality rate was 23% in the low-dose group and 47% in the moderate-dose group (aOR, 5.45).

There was no significant interaction between ASA and heparin on the primary outcome and on sICH occurrence.
 

‘A unique trial’

“MR CLEAN-MED is a unique trial because it investigated a widely used treatment but until now without any proof of effectiveness,” said Dr. van der Steen. The researchers expect that their findings will have a strong impact on the management of patients with acute ischemic stroke. They suggest that the administration of antithrombotic agents during EVT be avoided.

“We consider it probable that the increased risk of sICH explains at least a part of the nonsignificant shift towards a worse functional outcome,” co-investigator Bob Roozenbeek, MD, PhD, a neurologist at the Erasmus Medical Center, said in an interview. “However, to make more definite statements, we will have to do more in-depth analyses.”

It remains unclear whether the periprocedural use of lower dosages of antithrombotic agents or of a single bolus of heparin could be safe and effective, said Dr. van der Steen.

To gain insight into these questions, the investigators will evaluate the effect of the medications and dosages examined in this trial on primary hemostasis and coagulation activity in the trial population. They also plan to examine the effect of primary hemostasis and coagulation activity on risk for sICH and functional outcome.

Enhancing the effectiveness of thrombectomy for acute ischemic stroke continues to be an important goal for stroke therapy, said Mark Fisher, MD, professor of neurology and pathology and laboratory medicine at the University of California, Irvine, who commented on the findings for this news organization.

At least three strategies are available: The use of ancillary antithrombotic medications, neuroprotection, and modulation of the vasoconstrictive properties of the microcirculation.

“Results of MR CLEAN-MED argue against the antithrombotic strategy,” said Dr. Fisher. “The alternate strategies remain viable, and results of interventions using those approaches are awaited with great interest.”

The study was funded by the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative and the Brain Foundation Netherlands. Funding also was provided by Stryker, Medtronic, and Cerenovus. Dr. van der Steen and Dr. Fisher have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Treatment with acetylsalicylic acid (ASA) or heparin is associated with an increased risk for symptomatic intracranial hemorrhage (sICH) in patients with ischemic stroke who are undergoing endovascular therapy (EVT), new data show.

In this population, ASA and heparin are each associated with an approximately doubled risk for sICH when administered during EVT.

“We did not find any evidence for a beneficial effect on functional outcome,” investigator Wouter van der Steen, MD, research physician and PhD student at Erasmus University Medical Center, Rotterdam, the Netherlands, told this news organization. The possibility that a positive effect would be observed if the trial were continued was considered negligible, he added.

The researchers stopped the trial for safety reasons and recommend avoiding the evaluated dosages of both medications during EVT for ischemic stroke, said Dr. van der Steen.

He presented the findings from the MR CLEAN-MED trial at the European Stroke Organisation Conference (ESOC) 2021, which was held online.
 

Trial stopped for safety

Previous research has supported the safety and efficacy of EVT for ischemic stroke. Still, more than 30% of patients do not recover, despite fast and complete recanalization. Incomplete microvascular reperfusion (IMR) could explain this incomplete recovery, the researchers note.

Microthrombi, which occlude distal vessels, and neutrophil extracellular traps can cause IMR. This problem can be reduced through treatment with ASA, which has an antithrombotic effect, or with heparin, which dissolves neutrophil extracellular traps, they add. Although these drugs are associated with good clinical outcomes, they entail an increased risk for sICH.

The investigators conducted the multicenter, randomized controlled MR CLEAN-MED trial to evaluate the effect of intravenous (IV) ASA and heparin, alone or in combination, during EVT for acute ischemic stroke. Treatment was open label, but outcome assessment was blinded. Eligible participants were adults with a National Institutes of Health Stroke Scale (NIHSS) score of greater than or equal to 2 and an anterior circulation large-vessel occlusion for whom EVT could be initiated in fewer than 6 hours.

Investigators randomly assigned patients to receive or not to receive ASA. Within each of these two treatment groups, patients were randomly assigned to receive no heparin, low-dose heparin, or moderate-dose heparin.

ASA was given in a loading dose of 300 mg. Patients who were given low-dose heparin received a loading dose of 5,000 IU followed by 500 IU/h for 6 hours. Patients who received moderate-dose heparin were given a loading dose of 5,000 IU followed by 1,250 IU/h for 6 hours.

The study’s primary outcome was Modified Rankin Scale (mRS) score at 90 days. Secondary outcomes were NIHSS score at 24 hours, NIHSS score at 5 to 7 days, and recanalization grade at 24 hours on CT angiography or MRI. The primary safety outcomes were sICH and death within 90 days.

An independent, unblinded data and safety monitoring board (DSMB) assessed the risk for the primary safety outcomes throughout the trial. The board performed interim analyses of safety and efficacy for every 300 patients.

After the fourth safety assessment, the DSMB recommended that enrollment in the moderate-dose heparin arm be discontinued for safety reasons. Enrollment in other arms continued.

After the second interim analysis, the DSMB advised that the trial steering committee be unblinded to decide whether to stop or continue the trial. The steering committee decided to stop the trial for reasons of safety.
 

Increased risk for sICH

In all, 628 patients were included in the study. The ASA groups included 310 patients, and the no-ASA groups included 318 patients. In all, 332 participants received heparin, and 296 received no heparin.

The demographic characteristics were well balanced between groups. The population’s median age was 73 years, and about 53% were men. The median baseline NIHSS score was approximately 15. About 74% of patients received IV thrombolysis. The median baseline Alberta Stroke Program Early CT Scan score was 9.

The investigators observed a slight shift toward worse outcome in the ASA group, compared with the no-ASA group (adjusted OR, 0.91). In addition, the ASA group had a significantly increased risk for sICH, compared with the no-ASA group (14% vs. 7.2%; aOR, 1.95).

Patients in the ASA group were less likely to have good functional outcome (mRS of 0 to 2; aOR, 0.76), and the mortality rate tended to be higher.

The researchers found a nonsignificant shift toward a worse functional outcome in the heparin group, compared with the no-heparin group (aOR, 0.81). The risk for sICH was significantly higher in the heparin group, compared with the no-heparin group (13% vs. 7.4%; aOR, 2.00).

Patients in the heparin group were also less likely to have a good functional outcome (aOR, 0.78), and there was a nonsignificant increase in risk for death among those patients.

The rate of sICH was 11% in the group that received low-dose heparin; it was 26% in the group that received moderate-dose heparin (aOR, 6.05). The mortality rate was 23% in the low-dose group and 47% in the moderate-dose group (aOR, 5.45).

There was no significant interaction between ASA and heparin on the primary outcome and on sICH occurrence.
 

‘A unique trial’

“MR CLEAN-MED is a unique trial because it investigated a widely used treatment but until now without any proof of effectiveness,” said Dr. van der Steen. The researchers expect that their findings will have a strong impact on the management of patients with acute ischemic stroke. They suggest that the administration of antithrombotic agents during EVT be avoided.

“We consider it probable that the increased risk of sICH explains at least a part of the nonsignificant shift towards a worse functional outcome,” co-investigator Bob Roozenbeek, MD, PhD, a neurologist at the Erasmus Medical Center, said in an interview. “However, to make more definite statements, we will have to do more in-depth analyses.”

It remains unclear whether the periprocedural use of lower dosages of antithrombotic agents or of a single bolus of heparin could be safe and effective, said Dr. van der Steen.

To gain insight into these questions, the investigators will evaluate the effect of the medications and dosages examined in this trial on primary hemostasis and coagulation activity in the trial population. They also plan to examine the effect of primary hemostasis and coagulation activity on risk for sICH and functional outcome.

Enhancing the effectiveness of thrombectomy for acute ischemic stroke continues to be an important goal for stroke therapy, said Mark Fisher, MD, professor of neurology and pathology and laboratory medicine at the University of California, Irvine, who commented on the findings for this news organization.

At least three strategies are available: The use of ancillary antithrombotic medications, neuroprotection, and modulation of the vasoconstrictive properties of the microcirculation.

“Results of MR CLEAN-MED argue against the antithrombotic strategy,” said Dr. Fisher. “The alternate strategies remain viable, and results of interventions using those approaches are awaited with great interest.”

The study was funded by the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative and the Brain Foundation Netherlands. Funding also was provided by Stryker, Medtronic, and Cerenovus. Dr. van der Steen and Dr. Fisher have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

[email protected]

One month of dual antiplatelet therapy followed by 11 months of clopidogrel monotherapy failed to prove noninferiority to 12 unbroken months of DAPT for net clinical benefit in a multicenter Japanese trial that randomized more than 4,000 patients who underwent percutaneous coronary intervention (PCI) after a recent acute coronary syndrome episode.

© Astrid Gast/Thinkstock

The outcomes showed that while truncating DAPT duration could, as expected, cut major bleeding episodes roughly in half, it also led to a significant near doubling of myocardial infarction and showed a strong trend toward also increasing a composite tally of several types of ischemic events. These data were reported this week by Hirotoshi Watanabe, MD, PhD, at the virtual annual congress of the European Society of Cardiology. All study patients had undergone PCI with cobalt-chromium everolimus-eluting (CCEE) coronary stents (Xience).

These findings from the STOPDAPT-2 ACS trial highlighted the limits of minimizing DAPT after PCI in patients at high ischemic risk, such as after an acute coronary syndrome (ACS) event.

It also was a counterpoint to a somewhat similar study also reported at the congress, MASTER DAPT, which showed that 1 month of DAPT was noninferior to 3 or more months of DAPT for net clinical benefit in a distinctly different population of patients undergoing PCI (and using a different type of coronary stent) – those at high bleeding risk and with only about half the patients having had a recent ACS.

The results of STOPDAPT-2 ACS “do not support use of 1 month of DAPT followed by P2Y12 inhibitor monotherapy with clopidogrel compared with standard DAPT,” commented Robert A. Byrne, MBBCh, PhD, designated discussant for the report and professor at the RCSI University of Medicine and Health Sciences in Dublin.

“Although major bleeding was significantly reduced with this approach, there appeared to be a significant increase in adverse ischemic events, and there was a clear signal in relation to overall mortality, the ultimate arbiter of net clinical benefit,” added Dr. Byrne, who is also director of cardiology at Mater Private Hospital in Dublin.

He suggested that a mechanistic explanation for the signal of harm seem in STOPDAPT-2 ACS was the relatively low potency of clopidogrel (Plavix) as an antiplatelet agent, compared with other P2Y12 inhibitors such as prasugrel (Effient) and ticagrelor (Brilinta), as well as the genetically driven variability in response to clopidogrel that’s also absent with alternative agents.

These between-agent differences are of “particular clinical relevance in the early aftermath of an ACS event,” Dr. Byrne said.
 

12-month DAPT remains standard for PCI patients with recent ACS

The totality of clinical evidence “continues to support a standard 12-month duration of DAPT – using aspirin and either prasugrel or ticagrelor – as the preferred default approach,” Dr. Byrne concluded.

He acknowledged that an abbreviated duration of DAPT followed by P2Y12 inhibitor monotherapy “might be considered as an alternative.” In patients following an ACS event who do not have high risk for bleeding, he said, the minimum duration of DAPT should be at least 3 months and with preferential use of a more potent P2Y12 inhibitor.

Twelve months of DAPT treatment with aspirin and a P2Y12 inhibitor for patients following PCI “remains the standard of care in guidelines,” noted Marco Roffi, MD, a second discussant at the congress. But several questions remain, he added, such as which P2Y12 inhibitors work best and whether DAPT can be less than 12 months.

“The investigators [for STOPDAPT-2 ACS] pushed these questions to the limit with 1 month of DAPT and clopidogrel monotherapy,” said Dr. Roffi, professor and director of interventional cardiology at University Hospital, Geneva.

“This was a risky bet, and the investigators lost by not proving noninferiority and with excess ischemic events,” he commented.
 

First came STOPDAPT-2

Dr. Watanabe and colleagues designed STOPDAPT-2 ACS as a follow-up to their prior STOPDAPT-2 trial, which randomly assigned slightly more than 3000 patients at 90 Japanese centers to the identical two treatment options: 1 month of DAPT followed by 11 months of clopidogrel monotherapy or 12 months of DAPT, except the trial enrolled all types of patients undergoing PCI. This meant that a minority, 38%, had a recent ACS event, while the remaining patients had chronic coronary artery disease. As in STOPDAPT-2 ACS, all patients in STOPDAPT-2 had received a CCEE stent.

STOPDAPT-2 also used the same primary endpoint to tally net clinical benefit as STOPDAPT-2 ACS: cardiovascular death, MI, stroke of any type, definite stent thrombosis, or TIMI major or minor bleeding classification.

In STOPDAPT-2, using the mixed population with both recent ACS and chronic coronary disease, the regimen of 1 month of DAPT followed by 11 months of clopidogrel monotherapy was both noninferior to and superior to 12 months of DAPT, reducing the net adverse-event tally by 36% relative to 12-month DAPT and by an absolute reduction of 1.34%, as reported in 2019.

Despite this superiority, the results from STOPDAPT-2 had little impact on global practice, commented Kurt Huber, MD, professor and director of the cardiology ICU at the Medical University of Vienna.

“STOP-DAPT-2 did not give us a clear message with respect to reducing antiplatelet treatment after 1 month. I thought that for ACS patients 1 month might be too short,” Dr. Huber said during a press briefing.
 

Focusing on post-ACS

To directly address this issue, the investigators launched STOPDAPT-2 ACS, which used the same design as the preceding study but only enrolled patients soon after an ACS event. The trial included for its main analysis 3,008 newly enrolled patients with recent ACS, and 1,161 patients who had a recent ACS event and had been randomly assigned in STOPDAPT-2, creating a total study cohort for the new analysis of 4136 patients treated and followed for the study’s full 12 months.

The patients averaged 67 years old, 79% were men, and 30% had diabetes. About 56% had a recent ST-elevation MI, about 20% a recent non–ST-elevation MI, and the remaining 24% had unstable angina. For their unspecified P2Y12 inhibition, roughly half the patients received clopidogrel and the rest received prasugrel. Adherence to the two assigned treatment regimens was very good, with a very small number of patients not adhering to their assigned protocol.

The composite adverse event incidence over 12 months was 3.2% among those who received 1-month DAPT and 2.83% in those on DAPT for 12 months, a difference that failed to achieve the prespecified definition of noninferiority for 1-month DAPT, reported Dr. Watanabe, an interventional cardiologist at Kyoto University.

The ischemic event composite was 50% lower among those on 12-month DAPT, compared with 1 month of DAPT, a difference that just missed significance. The rate of MI was 91% higher with 1-month DAPT, compared with 12 months, a significant difference.

One-month DAPT also significantly reduced the primary measure of bleeding events – the combination of TIMI major and minor bleeds – by a significant 54%, compared with 12-month DAPT. A second metric of clinically meaningful bleeds, those that meet either the type 3 or 5 definition of the Bleeding Academic Research Consortium, were reduced by a significant 59% by 1-month DAPT, compared with 12 months of DAPT.

The new findings from STOPDAPT-2 ACS contrasted with those from MASTER DAPT, but in an explicable way that related to different patient types, different P2Y12 inhibitors, different treatment durations, and different stents.

“We’ve seen in MASTER DAPT that if you use the right stent and use ticagrelor for monotherapy there may be some ability to shorten DAPT, but we still do not know what would happen in patients with very high ischemic risk,” concluded Dr. Huber.

“A reduction in DAPT duration might work in patients without high bleeding risk, but I would exclude patients with very high ischemic risk,” he added. “I also can’t tell you whether 1 month or 3 months is the right approach, and I think clopidogrel is not the right drug to use for monotherapy after ACS.”

STOPDAPT-2 and STOPDAPT-2 ACS were both sponsored by Abbott Vascular, which markets the CCEE (Xience) stents used in both studies. Dr. Watanabe has received lecture fees from Abbott and from Daiichi-Sankyo. Dr. Byrne has received research funding from Abbott Vascular as well as from Biosensors, Biotronik, and Boston Scientific. Roffi has received research funding from Biotronik, Boston Scientific, GE Healthcare, Medtronic, and Terumo. Dr. Huber has received lecture fees from AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, Eli Lilly, Pfizer, Sanofi-Aventis, and The Medicines Company.

A version of this article first appeared on Medscape.com.

One month of dual antiplatelet therapy followed by 11 months of clopidogrel monotherapy failed to prove noninferiority to 12 unbroken months of DAPT for net clinical benefit in a multicenter Japanese trial that randomized more than 4,000 patients who underwent percutaneous coronary intervention (PCI) after a recent acute coronary syndrome episode.

© Astrid Gast/Thinkstock

The outcomes showed that while truncating DAPT duration could, as expected, cut major bleeding episodes roughly in half, it also led to a significant near doubling of myocardial infarction and showed a strong trend toward also increasing a composite tally of several types of ischemic events. These data were reported this week by Hirotoshi Watanabe, MD, PhD, at the virtual annual congress of the European Society of Cardiology. All study patients had undergone PCI with cobalt-chromium everolimus-eluting (CCEE) coronary stents (Xience).

These findings from the STOPDAPT-2 ACS trial highlighted the limits of minimizing DAPT after PCI in patients at high ischemic risk, such as after an acute coronary syndrome (ACS) event.

It also was a counterpoint to a somewhat similar study also reported at the congress, MASTER DAPT, which showed that 1 month of DAPT was noninferior to 3 or more months of DAPT for net clinical benefit in a distinctly different population of patients undergoing PCI (and using a different type of coronary stent) – those at high bleeding risk and with only about half the patients having had a recent ACS.

The results of STOPDAPT-2 ACS “do not support use of 1 month of DAPT followed by P2Y12 inhibitor monotherapy with clopidogrel compared with standard DAPT,” commented Robert A. Byrne, MBBCh, PhD, designated discussant for the report and professor at the RCSI University of Medicine and Health Sciences in Dublin.

“Although major bleeding was significantly reduced with this approach, there appeared to be a significant increase in adverse ischemic events, and there was a clear signal in relation to overall mortality, the ultimate arbiter of net clinical benefit,” added Dr. Byrne, who is also director of cardiology at Mater Private Hospital in Dublin.

He suggested that a mechanistic explanation for the signal of harm seem in STOPDAPT-2 ACS was the relatively low potency of clopidogrel (Plavix) as an antiplatelet agent, compared with other P2Y12 inhibitors such as prasugrel (Effient) and ticagrelor (Brilinta), as well as the genetically driven variability in response to clopidogrel that’s also absent with alternative agents.

These between-agent differences are of “particular clinical relevance in the early aftermath of an ACS event,” Dr. Byrne said.
 

12-month DAPT remains standard for PCI patients with recent ACS

The totality of clinical evidence “continues to support a standard 12-month duration of DAPT – using aspirin and either prasugrel or ticagrelor – as the preferred default approach,” Dr. Byrne concluded.

He acknowledged that an abbreviated duration of DAPT followed by P2Y12 inhibitor monotherapy “might be considered as an alternative.” In patients following an ACS event who do not have high risk for bleeding, he said, the minimum duration of DAPT should be at least 3 months and with preferential use of a more potent P2Y12 inhibitor.

Twelve months of DAPT treatment with aspirin and a P2Y12 inhibitor for patients following PCI “remains the standard of care in guidelines,” noted Marco Roffi, MD, a second discussant at the congress. But several questions remain, he added, such as which P2Y12 inhibitors work best and whether DAPT can be less than 12 months.

“The investigators [for STOPDAPT-2 ACS] pushed these questions to the limit with 1 month of DAPT and clopidogrel monotherapy,” said Dr. Roffi, professor and director of interventional cardiology at University Hospital, Geneva.

“This was a risky bet, and the investigators lost by not proving noninferiority and with excess ischemic events,” he commented.
 

First came STOPDAPT-2

Dr. Watanabe and colleagues designed STOPDAPT-2 ACS as a follow-up to their prior STOPDAPT-2 trial, which randomly assigned slightly more than 3000 patients at 90 Japanese centers to the identical two treatment options: 1 month of DAPT followed by 11 months of clopidogrel monotherapy or 12 months of DAPT, except the trial enrolled all types of patients undergoing PCI. This meant that a minority, 38%, had a recent ACS event, while the remaining patients had chronic coronary artery disease. As in STOPDAPT-2 ACS, all patients in STOPDAPT-2 had received a CCEE stent.

STOPDAPT-2 also used the same primary endpoint to tally net clinical benefit as STOPDAPT-2 ACS: cardiovascular death, MI, stroke of any type, definite stent thrombosis, or TIMI major or minor bleeding classification.

In STOPDAPT-2, using the mixed population with both recent ACS and chronic coronary disease, the regimen of 1 month of DAPT followed by 11 months of clopidogrel monotherapy was both noninferior to and superior to 12 months of DAPT, reducing the net adverse-event tally by 36% relative to 12-month DAPT and by an absolute reduction of 1.34%, as reported in 2019.

Despite this superiority, the results from STOPDAPT-2 had little impact on global practice, commented Kurt Huber, MD, professor and director of the cardiology ICU at the Medical University of Vienna.

“STOP-DAPT-2 did not give us a clear message with respect to reducing antiplatelet treatment after 1 month. I thought that for ACS patients 1 month might be too short,” Dr. Huber said during a press briefing.
 

Focusing on post-ACS

To directly address this issue, the investigators launched STOPDAPT-2 ACS, which used the same design as the preceding study but only enrolled patients soon after an ACS event. The trial included for its main analysis 3,008 newly enrolled patients with recent ACS, and 1,161 patients who had a recent ACS event and had been randomly assigned in STOPDAPT-2, creating a total study cohort for the new analysis of 4136 patients treated and followed for the study’s full 12 months.

The patients averaged 67 years old, 79% were men, and 30% had diabetes. About 56% had a recent ST-elevation MI, about 20% a recent non–ST-elevation MI, and the remaining 24% had unstable angina. For their unspecified P2Y12 inhibition, roughly half the patients received clopidogrel and the rest received prasugrel. Adherence to the two assigned treatment regimens was very good, with a very small number of patients not adhering to their assigned protocol.

The composite adverse event incidence over 12 months was 3.2% among those who received 1-month DAPT and 2.83% in those on DAPT for 12 months, a difference that failed to achieve the prespecified definition of noninferiority for 1-month DAPT, reported Dr. Watanabe, an interventional cardiologist at Kyoto University.

The ischemic event composite was 50% lower among those on 12-month DAPT, compared with 1 month of DAPT, a difference that just missed significance. The rate of MI was 91% higher with 1-month DAPT, compared with 12 months, a significant difference.

One-month DAPT also significantly reduced the primary measure of bleeding events – the combination of TIMI major and minor bleeds – by a significant 54%, compared with 12-month DAPT. A second metric of clinically meaningful bleeds, those that meet either the type 3 or 5 definition of the Bleeding Academic Research Consortium, were reduced by a significant 59% by 1-month DAPT, compared with 12 months of DAPT.

The new findings from STOPDAPT-2 ACS contrasted with those from MASTER DAPT, but in an explicable way that related to different patient types, different P2Y12 inhibitors, different treatment durations, and different stents.

“We’ve seen in MASTER DAPT that if you use the right stent and use ticagrelor for monotherapy there may be some ability to shorten DAPT, but we still do not know what would happen in patients with very high ischemic risk,” concluded Dr. Huber.

“A reduction in DAPT duration might work in patients without high bleeding risk, but I would exclude patients with very high ischemic risk,” he added. “I also can’t tell you whether 1 month or 3 months is the right approach, and I think clopidogrel is not the right drug to use for monotherapy after ACS.”

STOPDAPT-2 and STOPDAPT-2 ACS were both sponsored by Abbott Vascular, which markets the CCEE (Xience) stents used in both studies. Dr. Watanabe has received lecture fees from Abbott and from Daiichi-Sankyo. Dr. Byrne has received research funding from Abbott Vascular as well as from Biosensors, Biotronik, and Boston Scientific. Roffi has received research funding from Biotronik, Boston Scientific, GE Healthcare, Medtronic, and Terumo. Dr. Huber has received lecture fees from AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, Eli Lilly, Pfizer, Sanofi-Aventis, and The Medicines Company.

A version of this article first appeared on Medscape.com.

One month of dual antiplatelet therapy followed by 11 months of clopidogrel monotherapy failed to prove noninferiority to 12 unbroken months of DAPT for net clinical benefit in a multicenter Japanese trial that randomized more than 4,000 patients who underwent percutaneous coronary intervention (PCI) after a recent acute coronary syndrome episode.

© Astrid Gast/Thinkstock

The outcomes showed that while truncating DAPT duration could, as expected, cut major bleeding episodes roughly in half, it also led to a significant near doubling of myocardial infarction and showed a strong trend toward also increasing a composite tally of several types of ischemic events. These data were reported this week by Hirotoshi Watanabe, MD, PhD, at the virtual annual congress of the European Society of Cardiology. All study patients had undergone PCI with cobalt-chromium everolimus-eluting (CCEE) coronary stents (Xience).

These findings from the STOPDAPT-2 ACS trial highlighted the limits of minimizing DAPT after PCI in patients at high ischemic risk, such as after an acute coronary syndrome (ACS) event.

It also was a counterpoint to a somewhat similar study also reported at the congress, MASTER DAPT, which showed that 1 month of DAPT was noninferior to 3 or more months of DAPT for net clinical benefit in a distinctly different population of patients undergoing PCI (and using a different type of coronary stent) – those at high bleeding risk and with only about half the patients having had a recent ACS.

The results of STOPDAPT-2 ACS “do not support use of 1 month of DAPT followed by P2Y12 inhibitor monotherapy with clopidogrel compared with standard DAPT,” commented Robert A. Byrne, MBBCh, PhD, designated discussant for the report and professor at the RCSI University of Medicine and Health Sciences in Dublin.

“Although major bleeding was significantly reduced with this approach, there appeared to be a significant increase in adverse ischemic events, and there was a clear signal in relation to overall mortality, the ultimate arbiter of net clinical benefit,” added Dr. Byrne, who is also director of cardiology at Mater Private Hospital in Dublin.

He suggested that a mechanistic explanation for the signal of harm seem in STOPDAPT-2 ACS was the relatively low potency of clopidogrel (Plavix) as an antiplatelet agent, compared with other P2Y12 inhibitors such as prasugrel (Effient) and ticagrelor (Brilinta), as well as the genetically driven variability in response to clopidogrel that’s also absent with alternative agents.

These between-agent differences are of “particular clinical relevance in the early aftermath of an ACS event,” Dr. Byrne said.
 

12-month DAPT remains standard for PCI patients with recent ACS

The totality of clinical evidence “continues to support a standard 12-month duration of DAPT – using aspirin and either prasugrel or ticagrelor – as the preferred default approach,” Dr. Byrne concluded.

He acknowledged that an abbreviated duration of DAPT followed by P2Y12 inhibitor monotherapy “might be considered as an alternative.” In patients following an ACS event who do not have high risk for bleeding, he said, the minimum duration of DAPT should be at least 3 months and with preferential use of a more potent P2Y12 inhibitor.

Twelve months of DAPT treatment with aspirin and a P2Y12 inhibitor for patients following PCI “remains the standard of care in guidelines,” noted Marco Roffi, MD, a second discussant at the congress. But several questions remain, he added, such as which P2Y12 inhibitors work best and whether DAPT can be less than 12 months.

“The investigators [for STOPDAPT-2 ACS] pushed these questions to the limit with 1 month of DAPT and clopidogrel monotherapy,” said Dr. Roffi, professor and director of interventional cardiology at University Hospital, Geneva.

“This was a risky bet, and the investigators lost by not proving noninferiority and with excess ischemic events,” he commented.
 

First came STOPDAPT-2

Dr. Watanabe and colleagues designed STOPDAPT-2 ACS as a follow-up to their prior STOPDAPT-2 trial, which randomly assigned slightly more than 3000 patients at 90 Japanese centers to the identical two treatment options: 1 month of DAPT followed by 11 months of clopidogrel monotherapy or 12 months of DAPT, except the trial enrolled all types of patients undergoing PCI. This meant that a minority, 38%, had a recent ACS event, while the remaining patients had chronic coronary artery disease. As in STOPDAPT-2 ACS, all patients in STOPDAPT-2 had received a CCEE stent.

STOPDAPT-2 also used the same primary endpoint to tally net clinical benefit as STOPDAPT-2 ACS: cardiovascular death, MI, stroke of any type, definite stent thrombosis, or TIMI major or minor bleeding classification.

In STOPDAPT-2, using the mixed population with both recent ACS and chronic coronary disease, the regimen of 1 month of DAPT followed by 11 months of clopidogrel monotherapy was both noninferior to and superior to 12 months of DAPT, reducing the net adverse-event tally by 36% relative to 12-month DAPT and by an absolute reduction of 1.34%, as reported in 2019.

Despite this superiority, the results from STOPDAPT-2 had little impact on global practice, commented Kurt Huber, MD, professor and director of the cardiology ICU at the Medical University of Vienna.

“STOP-DAPT-2 did not give us a clear message with respect to reducing antiplatelet treatment after 1 month. I thought that for ACS patients 1 month might be too short,” Dr. Huber said during a press briefing.
 

Focusing on post-ACS

To directly address this issue, the investigators launched STOPDAPT-2 ACS, which used the same design as the preceding study but only enrolled patients soon after an ACS event. The trial included for its main analysis 3,008 newly enrolled patients with recent ACS, and 1,161 patients who had a recent ACS event and had been randomly assigned in STOPDAPT-2, creating a total study cohort for the new analysis of 4136 patients treated and followed for the study’s full 12 months.

The patients averaged 67 years old, 79% were men, and 30% had diabetes. About 56% had a recent ST-elevation MI, about 20% a recent non–ST-elevation MI, and the remaining 24% had unstable angina. For their unspecified P2Y12 inhibition, roughly half the patients received clopidogrel and the rest received prasugrel. Adherence to the two assigned treatment regimens was very good, with a very small number of patients not adhering to their assigned protocol.

The composite adverse event incidence over 12 months was 3.2% among those who received 1-month DAPT and 2.83% in those on DAPT for 12 months, a difference that failed to achieve the prespecified definition of noninferiority for 1-month DAPT, reported Dr. Watanabe, an interventional cardiologist at Kyoto University.

The ischemic event composite was 50% lower among those on 12-month DAPT, compared with 1 month of DAPT, a difference that just missed significance. The rate of MI was 91% higher with 1-month DAPT, compared with 12 months, a significant difference.

One-month DAPT also significantly reduced the primary measure of bleeding events – the combination of TIMI major and minor bleeds – by a significant 54%, compared with 12-month DAPT. A second metric of clinically meaningful bleeds, those that meet either the type 3 or 5 definition of the Bleeding Academic Research Consortium, were reduced by a significant 59% by 1-month DAPT, compared with 12 months of DAPT.

The new findings from STOPDAPT-2 ACS contrasted with those from MASTER DAPT, but in an explicable way that related to different patient types, different P2Y12 inhibitors, different treatment durations, and different stents.

“We’ve seen in MASTER DAPT that if you use the right stent and use ticagrelor for monotherapy there may be some ability to shorten DAPT, but we still do not know what would happen in patients with very high ischemic risk,” concluded Dr. Huber.

“A reduction in DAPT duration might work in patients without high bleeding risk, but I would exclude patients with very high ischemic risk,” he added. “I also can’t tell you whether 1 month or 3 months is the right approach, and I think clopidogrel is not the right drug to use for monotherapy after ACS.”

STOPDAPT-2 and STOPDAPT-2 ACS were both sponsored by Abbott Vascular, which markets the CCEE (Xience) stents used in both studies. Dr. Watanabe has received lecture fees from Abbott and from Daiichi-Sankyo. Dr. Byrne has received research funding from Abbott Vascular as well as from Biosensors, Biotronik, and Boston Scientific. Roffi has received research funding from Biotronik, Boston Scientific, GE Healthcare, Medtronic, and Terumo. Dr. Huber has received lecture fees from AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, Eli Lilly, Pfizer, Sanofi-Aventis, and The Medicines Company.

A version of this article first appeared on Medscape.com.

Carotid artery stenting (CAS) and carotid endarterectomy (CEA) provided comparable outcomes over time in asymptomatic patients receiving good medical therapy in the largest trial to date of what to do with severe carotid artery narrowing that is yet to cause a stroke.

aaM Photography, Ltd./iStock

Among more than 3,600 patients, stenting and surgery performed by experienced physicians involved a 1.0% risk for causing disabling stroke or death within 30 days.

The annual rate of fatal or disabling strokes was about 0.5% with either procedure over an average 5 years’ follow-up – essentially halving the annual stroke risk had neither procedure been performed, according to Alison Halliday, MD, principal investigator of the Asymptomatic Carotid Surgery Trial-2 (ACST-2).

The results were reported Aug. 29 in a Hot Line session at the virtual annual congress of the European Society of Cardiology and published simultaneously online in The Lancet.

Session chair Gilles Montalescot, MD, Sorbonne University, Paris, noted that ACST-2 doubled the number of randomly assigned patients with asymptomatic carotid stenosis studied in previous trials, “so, a huge contribution to the evidence base in this field and apparently good news for both revascularization techniques.”
 

Thirty-day and 5-year outcomes

The trial was conducted in 33 countries between January 2008 and December 2020, enrolling 3,625 patients (70% were male; mean age, 70 years) with carotid stenosis of at least 60% on ultrasonography, in whom stenting or surgery was suitable but both the doctor and patient were “substantially uncertain” which procedure to prefer.

Among the 1,811 patients assigned to stenting, 87% underwent the procedure at a median of 14 days; 6% crossed over to surgery, typically because of a highly calcified lesion or a more tortuous carotid than anticipated; and 6% had no intervention.

Among the 1,814 patients assigned to surgery, 92% had the procedure at a median of 14 days; 3% crossed over to stenting, typically because of patient or doctor preference or reluctance to undergo general anesthesia; and 4% had no intervention.

Patients without complications who had stenting stayed on average 1 day less than did those undergoing surgery.

During an earlier press briefing, Dr. Halliday highlighted the need for procedural competency and said doctors had to submit a record of their CEA or CAS experience and, consistent with current guidelines, had to demonstrate an independently verified stroke or death rate of 6% or less for symptomatic patients and 3% or lower for asymptomatic patients.

The results showed the 30-day risk for death, myocardial infarction (MI), or any stroke was 3.9% with carotid stenting and 3.2% with surgery (P = .26).

But with stenting, there was a slightly higher risk for procedural nondisabling strokes (48 vs. 29; P = .03), including 15 strokes vs. 5 strokes, respectively, that left patients with no residual symptoms. This is “consistent with large, recent nationally representative registry data,” observed Dr. Halliday, of the University of Oxford (England).

For those undergoing surgery, cranial nerve palsies were reported in 5.4% vs. no patients undergoing stenting.

At 5 years, the nonprocedural fatal or disabling stroke rate was 2.5% in each group (rate ratio [RR], 0.98; P = .91), with any nonprocedural stroke occurring in 5.3% of patients with stenting vs. 4.5% with surgery (RR, 1.16; P = .33).

The investigators performed a meta-analysis combining the ACST-2 results with those of eight prior trials (four in asymptomatic and four in symptomatic patients) that yielded a similar nonsignificant result for any nonprocedural stroke (RR, 1.11; P = .21).

Based on the results from ACST-2 plus the major trials, stenting and surgery involve “similar risks and similar benefits,” Dr. Halliday concluded.

Discussant Marco Roffi, MD, University Hospital of Geneva, said, “In centers with documented expertise, carotid artery stenting should be offered as an alternative to carotid endarterectomy in patients with asymptomatic stenosis and suitable anatomy.”

While the trial provides “good news” for patients, he pointed out that a reduction in the sample size from 5,000 to 3,625 limited the statistical power and that enrollment over a long period of time may have introduced confounders, such as changes in equipment technique, and medical therapy.

Also, many centers enrolled few patients, raising the concern over low-volume centers and operators, Dr. Roffi said. “We know that 8% of the centers enrolled 39% of the patients,” and “information on the credentialing and experience of the interventionalists was limited.”

Further, a lack of systematic MI assessment may have favored the surgery group, and more recent developments in stenting with the potential of reducing periprocedural stroke were rarely used, such as proximal emboli protection in only 15% and double-layer stents in 11%.

Friedhelm Beyersdorf, MD, University Hospital of Freiburg, Germany, said that, as a vascular surgeon, he finds it understandable that there might be a higher incidence of nonfatal strokes when treating carotid stenosis with stents, given the vulnerability of these lesions.

“Nevertheless, the main conclusion from the entire study is that carotid artery treatment is extremely safe, it has to be done in order to avoid strokes, and, obviously, there seems to be an advantage for surgery in terms of nondisabling stroke,” he said.

Session chair Dr. Montalescot, however, said that what the study cannot address – and what was the subject of many online audience comments – is whether either intervention should be performed in these patients. 

Unlike earlier trials comparing interventions to medical therapy, Dr. Halliday said ACST-2 enrolled patients for whom the decision had been made that revascularization was needed. In addition, 99%-100% were receiving antithrombotic therapy at baseline, 85%-90% were receiving antihypertensives, and about 85% were taking statins.

Longer-term follow-up should provide a better picture of the nonprocedural stroke risk, with patients asked annually about exactly what medications and doses they are taking, she said.

“We will have an enormous list of exactly what’s gone on and the intensity of that therapy, which is, of course, much more intense than when we carried out our first trial. But these were people in whom a procedure was thought to be necessary,” she noted.

When asked during the press conference which procedure she would choose, Dr. Halliday, a surgeon, observed that patient preference is important but that the nature of the lesion itself often determines the optimal choice.

“If you know the competence of the people doing it is equal, then the less invasive procedure – providing it has good long-term viability, and that’s why we’re following for 10 years – is the more important,” she added.

The study was funded by the UK Medical Research Council and Health Technology Assessment Programme. Dr. Halliday reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Carotid artery stenting (CAS) and carotid endarterectomy (CEA) provided comparable outcomes over time in asymptomatic patients receiving good medical therapy in the largest trial to date of what to do with severe carotid artery narrowing that is yet to cause a stroke.

aaM Photography, Ltd./iStock

Among more than 3,600 patients, stenting and surgery performed by experienced physicians involved a 1.0% risk for causing disabling stroke or death within 30 days.

The annual rate of fatal or disabling strokes was about 0.5% with either procedure over an average 5 years’ follow-up – essentially halving the annual stroke risk had neither procedure been performed, according to Alison Halliday, MD, principal investigator of the Asymptomatic Carotid Surgery Trial-2 (ACST-2).

The results were reported Aug. 29 in a Hot Line session at the virtual annual congress of the European Society of Cardiology and published simultaneously online in The Lancet.

Session chair Gilles Montalescot, MD, Sorbonne University, Paris, noted that ACST-2 doubled the number of randomly assigned patients with asymptomatic carotid stenosis studied in previous trials, “so, a huge contribution to the evidence base in this field and apparently good news for both revascularization techniques.”
 

Thirty-day and 5-year outcomes

The trial was conducted in 33 countries between January 2008 and December 2020, enrolling 3,625 patients (70% were male; mean age, 70 years) with carotid stenosis of at least 60% on ultrasonography, in whom stenting or surgery was suitable but both the doctor and patient were “substantially uncertain” which procedure to prefer.

Among the 1,811 patients assigned to stenting, 87% underwent the procedure at a median of 14 days; 6% crossed over to surgery, typically because of a highly calcified lesion or a more tortuous carotid than anticipated; and 6% had no intervention.

Among the 1,814 patients assigned to surgery, 92% had the procedure at a median of 14 days; 3% crossed over to stenting, typically because of patient or doctor preference or reluctance to undergo general anesthesia; and 4% had no intervention.

Patients without complications who had stenting stayed on average 1 day less than did those undergoing surgery.

During an earlier press briefing, Dr. Halliday highlighted the need for procedural competency and said doctors had to submit a record of their CEA or CAS experience and, consistent with current guidelines, had to demonstrate an independently verified stroke or death rate of 6% or less for symptomatic patients and 3% or lower for asymptomatic patients.

The results showed the 30-day risk for death, myocardial infarction (MI), or any stroke was 3.9% with carotid stenting and 3.2% with surgery (P = .26).

But with stenting, there was a slightly higher risk for procedural nondisabling strokes (48 vs. 29; P = .03), including 15 strokes vs. 5 strokes, respectively, that left patients with no residual symptoms. This is “consistent with large, recent nationally representative registry data,” observed Dr. Halliday, of the University of Oxford (England).

For those undergoing surgery, cranial nerve palsies were reported in 5.4% vs. no patients undergoing stenting.

At 5 years, the nonprocedural fatal or disabling stroke rate was 2.5% in each group (rate ratio [RR], 0.98; P = .91), with any nonprocedural stroke occurring in 5.3% of patients with stenting vs. 4.5% with surgery (RR, 1.16; P = .33).

The investigators performed a meta-analysis combining the ACST-2 results with those of eight prior trials (four in asymptomatic and four in symptomatic patients) that yielded a similar nonsignificant result for any nonprocedural stroke (RR, 1.11; P = .21).

Based on the results from ACST-2 plus the major trials, stenting and surgery involve “similar risks and similar benefits,” Dr. Halliday concluded.

Discussant Marco Roffi, MD, University Hospital of Geneva, said, “In centers with documented expertise, carotid artery stenting should be offered as an alternative to carotid endarterectomy in patients with asymptomatic stenosis and suitable anatomy.”

While the trial provides “good news” for patients, he pointed out that a reduction in the sample size from 5,000 to 3,625 limited the statistical power and that enrollment over a long period of time may have introduced confounders, such as changes in equipment technique, and medical therapy.

Also, many centers enrolled few patients, raising the concern over low-volume centers and operators, Dr. Roffi said. “We know that 8% of the centers enrolled 39% of the patients,” and “information on the credentialing and experience of the interventionalists was limited.”

Further, a lack of systematic MI assessment may have favored the surgery group, and more recent developments in stenting with the potential of reducing periprocedural stroke were rarely used, such as proximal emboli protection in only 15% and double-layer stents in 11%.

Friedhelm Beyersdorf, MD, University Hospital of Freiburg, Germany, said that, as a vascular surgeon, he finds it understandable that there might be a higher incidence of nonfatal strokes when treating carotid stenosis with stents, given the vulnerability of these lesions.

“Nevertheless, the main conclusion from the entire study is that carotid artery treatment is extremely safe, it has to be done in order to avoid strokes, and, obviously, there seems to be an advantage for surgery in terms of nondisabling stroke,” he said.

Session chair Dr. Montalescot, however, said that what the study cannot address – and what was the subject of many online audience comments – is whether either intervention should be performed in these patients. 

Unlike earlier trials comparing interventions to medical therapy, Dr. Halliday said ACST-2 enrolled patients for whom the decision had been made that revascularization was needed. In addition, 99%-100% were receiving antithrombotic therapy at baseline, 85%-90% were receiving antihypertensives, and about 85% were taking statins.

Longer-term follow-up should provide a better picture of the nonprocedural stroke risk, with patients asked annually about exactly what medications and doses they are taking, she said.

“We will have an enormous list of exactly what’s gone on and the intensity of that therapy, which is, of course, much more intense than when we carried out our first trial. But these were people in whom a procedure was thought to be necessary,” she noted.

When asked during the press conference which procedure she would choose, Dr. Halliday, a surgeon, observed that patient preference is important but that the nature of the lesion itself often determines the optimal choice.

“If you know the competence of the people doing it is equal, then the less invasive procedure – providing it has good long-term viability, and that’s why we’re following for 10 years – is the more important,” she added.

The study was funded by the UK Medical Research Council and Health Technology Assessment Programme. Dr. Halliday reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Carotid artery stenting (CAS) and carotid endarterectomy (CEA) provided comparable outcomes over time in asymptomatic patients receiving good medical therapy in the largest trial to date of what to do with severe carotid artery narrowing that is yet to cause a stroke.

aaM Photography, Ltd./iStock

Among more than 3,600 patients, stenting and surgery performed by experienced physicians involved a 1.0% risk for causing disabling stroke or death within 30 days.

The annual rate of fatal or disabling strokes was about 0.5% with either procedure over an average 5 years’ follow-up – essentially halving the annual stroke risk had neither procedure been performed, according to Alison Halliday, MD, principal investigator of the Asymptomatic Carotid Surgery Trial-2 (ACST-2).

The results were reported Aug. 29 in a Hot Line session at the virtual annual congress of the European Society of Cardiology and published simultaneously online in The Lancet.

Session chair Gilles Montalescot, MD, Sorbonne University, Paris, noted that ACST-2 doubled the number of randomly assigned patients with asymptomatic carotid stenosis studied in previous trials, “so, a huge contribution to the evidence base in this field and apparently good news for both revascularization techniques.”
 

Thirty-day and 5-year outcomes

The trial was conducted in 33 countries between January 2008 and December 2020, enrolling 3,625 patients (70% were male; mean age, 70 years) with carotid stenosis of at least 60% on ultrasonography, in whom stenting or surgery was suitable but both the doctor and patient were “substantially uncertain” which procedure to prefer.

Among the 1,811 patients assigned to stenting, 87% underwent the procedure at a median of 14 days; 6% crossed over to surgery, typically because of a highly calcified lesion or a more tortuous carotid than anticipated; and 6% had no intervention.

Among the 1,814 patients assigned to surgery, 92% had the procedure at a median of 14 days; 3% crossed over to stenting, typically because of patient or doctor preference or reluctance to undergo general anesthesia; and 4% had no intervention.

Patients without complications who had stenting stayed on average 1 day less than did those undergoing surgery.

During an earlier press briefing, Dr. Halliday highlighted the need for procedural competency and said doctors had to submit a record of their CEA or CAS experience and, consistent with current guidelines, had to demonstrate an independently verified stroke or death rate of 6% or less for symptomatic patients and 3% or lower for asymptomatic patients.

The results showed the 30-day risk for death, myocardial infarction (MI), or any stroke was 3.9% with carotid stenting and 3.2% with surgery (P = .26).

But with stenting, there was a slightly higher risk for procedural nondisabling strokes (48 vs. 29; P = .03), including 15 strokes vs. 5 strokes, respectively, that left patients with no residual symptoms. This is “consistent with large, recent nationally representative registry data,” observed Dr. Halliday, of the University of Oxford (England).

For those undergoing surgery, cranial nerve palsies were reported in 5.4% vs. no patients undergoing stenting.

At 5 years, the nonprocedural fatal or disabling stroke rate was 2.5% in each group (rate ratio [RR], 0.98; P = .91), with any nonprocedural stroke occurring in 5.3% of patients with stenting vs. 4.5% with surgery (RR, 1.16; P = .33).

The investigators performed a meta-analysis combining the ACST-2 results with those of eight prior trials (four in asymptomatic and four in symptomatic patients) that yielded a similar nonsignificant result for any nonprocedural stroke (RR, 1.11; P = .21).

Based on the results from ACST-2 plus the major trials, stenting and surgery involve “similar risks and similar benefits,” Dr. Halliday concluded.

Discussant Marco Roffi, MD, University Hospital of Geneva, said, “In centers with documented expertise, carotid artery stenting should be offered as an alternative to carotid endarterectomy in patients with asymptomatic stenosis and suitable anatomy.”

While the trial provides “good news” for patients, he pointed out that a reduction in the sample size from 5,000 to 3,625 limited the statistical power and that enrollment over a long period of time may have introduced confounders, such as changes in equipment technique, and medical therapy.

Also, many centers enrolled few patients, raising the concern over low-volume centers and operators, Dr. Roffi said. “We know that 8% of the centers enrolled 39% of the patients,” and “information on the credentialing and experience of the interventionalists was limited.”

Further, a lack of systematic MI assessment may have favored the surgery group, and more recent developments in stenting with the potential of reducing periprocedural stroke were rarely used, such as proximal emboli protection in only 15% and double-layer stents in 11%.

Friedhelm Beyersdorf, MD, University Hospital of Freiburg, Germany, said that, as a vascular surgeon, he finds it understandable that there might be a higher incidence of nonfatal strokes when treating carotid stenosis with stents, given the vulnerability of these lesions.

“Nevertheless, the main conclusion from the entire study is that carotid artery treatment is extremely safe, it has to be done in order to avoid strokes, and, obviously, there seems to be an advantage for surgery in terms of nondisabling stroke,” he said.

Session chair Dr. Montalescot, however, said that what the study cannot address – and what was the subject of many online audience comments – is whether either intervention should be performed in these patients. 

Unlike earlier trials comparing interventions to medical therapy, Dr. Halliday said ACST-2 enrolled patients for whom the decision had been made that revascularization was needed. In addition, 99%-100% were receiving antithrombotic therapy at baseline, 85%-90% were receiving antihypertensives, and about 85% were taking statins.

Longer-term follow-up should provide a better picture of the nonprocedural stroke risk, with patients asked annually about exactly what medications and doses they are taking, she said.

“We will have an enormous list of exactly what’s gone on and the intensity of that therapy, which is, of course, much more intense than when we carried out our first trial. But these were people in whom a procedure was thought to be necessary,” she noted.

When asked during the press conference which procedure she would choose, Dr. Halliday, a surgeon, observed that patient preference is important but that the nature of the lesion itself often determines the optimal choice.

“If you know the competence of the people doing it is equal, then the less invasive procedure – providing it has good long-term viability, and that’s why we’re following for 10 years – is the more important,” she added.

The study was funded by the UK Medical Research Council and Health Technology Assessment Programme. Dr. Halliday reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.