William James Frederick Iii, MD, PhD

 

Clinical Question: What are the risks of nonthoracic MRI in patients with pacemakers or implantable cardioverter-defibrillators (ICD) who are not preapproved by the Food and Drug Administration for MRI scanning?

Background: Implantable cardiovascular devices could suffer heating in MRI magnetic fields leading to cardiac thermal injury and changes in pacing properties. The FDA approves “MRI-conditional devices” deemed safe for MRI, but up to six million patients worldwide (and two million in the United States) have non–MRI conditional devices.

Study Design: A prospective, multicenter registry of patients with non–MRI conditional pacemakers or ICDs.

Setting: U.S. Centers participating in the MagnaSafe registry.

Synopsis: Adults with non–MRI conditional pacemakers (1000 cases) or ICDs (500 cases) implanted in the thorax after 2001 were scanned with nonthoracic MRI at 1.5 Tesla. Patients with abandoned or inactive leads, other implantable devices, and low batteries and pacing-dependent patients with ICDs were excluded.

Devices were interrogated before each MRI and set to either no pacing or asynchronous pacing with all tachycardia and bradycardia therapies deactivated. Primary endpoints included immediate death, generator or lead failure, loss of capture in paced patients, new arrhythmia, and generator reset.

No patients suffered death or device or lead failure. Six patients developed self-terminating atrial arrhythmias, while an additional six had partial pacemaker electrical reset. Several devices had detectable changes in battery voltage, lead impedance, pacing threshold, and P- or R-wave amplitude without evident clinical significance. Multiple MRIs caused no increase in adverse outcomes. This study suggests that patients with non–MRI conditional devices may be at low risk from nonthoracic imaging if appropriately screened with temporary pacemaker function modification before MRI.

Bottom Line: Appropriately screened and prepared patients with non–MRI conditional thoracic pacemakers or ICDs may be at low risk for complications from nonthoracic MRI at 1.5 Tesla.

Reference: Russo RJ, Costa HS, Silva PD, et al. Assessing the risks associated with MRI in patients with a pacemaker or defibrillator. N Engl J Med. 2017;376:755-64.

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.

 

Clinical Question: What are the risks of nonthoracic MRI in patients with pacemakers or implantable cardioverter-defibrillators (ICD) who are not preapproved by the Food and Drug Administration for MRI scanning?

Background: Implantable cardiovascular devices could suffer heating in MRI magnetic fields leading to cardiac thermal injury and changes in pacing properties. The FDA approves “MRI-conditional devices” deemed safe for MRI, but up to six million patients worldwide (and two million in the United States) have non–MRI conditional devices.

Study Design: A prospective, multicenter registry of patients with non–MRI conditional pacemakers or ICDs.

Setting: U.S. Centers participating in the MagnaSafe registry.

Synopsis: Adults with non–MRI conditional pacemakers (1000 cases) or ICDs (500 cases) implanted in the thorax after 2001 were scanned with nonthoracic MRI at 1.5 Tesla. Patients with abandoned or inactive leads, other implantable devices, and low batteries and pacing-dependent patients with ICDs were excluded.

Devices were interrogated before each MRI and set to either no pacing or asynchronous pacing with all tachycardia and bradycardia therapies deactivated. Primary endpoints included immediate death, generator or lead failure, loss of capture in paced patients, new arrhythmia, and generator reset.

No patients suffered death or device or lead failure. Six patients developed self-terminating atrial arrhythmias, while an additional six had partial pacemaker electrical reset. Several devices had detectable changes in battery voltage, lead impedance, pacing threshold, and P- or R-wave amplitude without evident clinical significance. Multiple MRIs caused no increase in adverse outcomes. This study suggests that patients with non–MRI conditional devices may be at low risk from nonthoracic imaging if appropriately screened with temporary pacemaker function modification before MRI.

Bottom Line: Appropriately screened and prepared patients with non–MRI conditional thoracic pacemakers or ICDs may be at low risk for complications from nonthoracic MRI at 1.5 Tesla.

Reference: Russo RJ, Costa HS, Silva PD, et al. Assessing the risks associated with MRI in patients with a pacemaker or defibrillator. N Engl J Med. 2017;376:755-64.

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.

 

Clinical Question: What are the risks of nonthoracic MRI in patients with pacemakers or implantable cardioverter-defibrillators (ICD) who are not preapproved by the Food and Drug Administration for MRI scanning?

Background: Implantable cardiovascular devices could suffer heating in MRI magnetic fields leading to cardiac thermal injury and changes in pacing properties. The FDA approves “MRI-conditional devices” deemed safe for MRI, but up to six million patients worldwide (and two million in the United States) have non–MRI conditional devices.

Study Design: A prospective, multicenter registry of patients with non–MRI conditional pacemakers or ICDs.

Setting: U.S. Centers participating in the MagnaSafe registry.

Synopsis: Adults with non–MRI conditional pacemakers (1000 cases) or ICDs (500 cases) implanted in the thorax after 2001 were scanned with nonthoracic MRI at 1.5 Tesla. Patients with abandoned or inactive leads, other implantable devices, and low batteries and pacing-dependent patients with ICDs were excluded.

Devices were interrogated before each MRI and set to either no pacing or asynchronous pacing with all tachycardia and bradycardia therapies deactivated. Primary endpoints included immediate death, generator or lead failure, loss of capture in paced patients, new arrhythmia, and generator reset.

No patients suffered death or device or lead failure. Six patients developed self-terminating atrial arrhythmias, while an additional six had partial pacemaker electrical reset. Several devices had detectable changes in battery voltage, lead impedance, pacing threshold, and P- or R-wave amplitude without evident clinical significance. Multiple MRIs caused no increase in adverse outcomes. This study suggests that patients with non–MRI conditional devices may be at low risk from nonthoracic imaging if appropriately screened with temporary pacemaker function modification before MRI.

Bottom Line: Appropriately screened and prepared patients with non–MRI conditional thoracic pacemakers or ICDs may be at low risk for complications from nonthoracic MRI at 1.5 Tesla.

Reference: Russo RJ, Costa HS, Silva PD, et al. Assessing the risks associated with MRI in patients with a pacemaker or defibrillator. N Engl J Med. 2017;376:755-64.

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.

 

Clinical Question: Does the Multinational Association for Supportive Care in Cancer (MASCC) or Clinical Index of Stable Febrile Neutropenia (CISNE) risk-stratification score better predict patient outcomes in patients presenting to emergency departments with febrile neutropenia?

Background: Risk-stratification metrics like the MASCC and CISNE identify subsets of relatively low-risk patients with febrile neutropenia after chemotherapy for treatment at home with empiric oral antibiotic therapy and close follow-up while awaiting results of infectious work-up. Prior studies have validated these tools for admitted, but not for ED, patients.

Study Design: Retrospective cohort study.

Setting: Two academic ED at National Institutes of Health–designated cancer centers.

Synopsis: Included patients (n = 230) were at least 16 years old with a documented fever of 38° C or greater related to chemotherapy and an absolute neutrophil count less than 1,000 cells/μL. MASCC and CISNE risk stratification scores were calculated based on the documentation from the ED and recent oncology clinic visits. Outcome measures included length of stay, upgrade in level of care, positive blood cultures, clinical deterioration, and death and were assessed for up to 30 days following discharge. Low-risk patients were defined as those who experienced no negative endpoints. The CISNE score was more specific than the MASCC in identifying low-risk patients (98.1% vs. 54.2%), suggesting that the CISNE may be useful for hospitalists in identifying patients who may be safely discharged with oral antibiotics and close follow-up.

Limitations include possible misclassification bias from indirect assessment of symptom severity, lack of recent ECOG scores for six patients in the CISNE arm, and possible undocumented symptoms during ED evaluation required for subsequent score calculation. Additionally, most patients in this study reported mild symptoms which weighted their MASCC classification toward low-risk.

Bottom Line: The CISNE score may aid in risk-stratification of patients with chemotherapy-related febrile neutropenia presenting to the ED.

Reference: Coyne CJ, Le V, Brennan JJ, et al. Application of the MASCC and CISNE risk-stratification scores to identify low-risk febrile neutropenic patients in the emergency department. Ann Emerg Med. Published online 29 Dec 2016. doi: 10.1016/j.annemergmed.2016.11.007.
 

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.

 

Clinical Question: Does the Multinational Association for Supportive Care in Cancer (MASCC) or Clinical Index of Stable Febrile Neutropenia (CISNE) risk-stratification score better predict patient outcomes in patients presenting to emergency departments with febrile neutropenia?

Background: Risk-stratification metrics like the MASCC and CISNE identify subsets of relatively low-risk patients with febrile neutropenia after chemotherapy for treatment at home with empiric oral antibiotic therapy and close follow-up while awaiting results of infectious work-up. Prior studies have validated these tools for admitted, but not for ED, patients.

Study Design: Retrospective cohort study.

Setting: Two academic ED at National Institutes of Health–designated cancer centers.

Synopsis: Included patients (n = 230) were at least 16 years old with a documented fever of 38° C or greater related to chemotherapy and an absolute neutrophil count less than 1,000 cells/μL. MASCC and CISNE risk stratification scores were calculated based on the documentation from the ED and recent oncology clinic visits. Outcome measures included length of stay, upgrade in level of care, positive blood cultures, clinical deterioration, and death and were assessed for up to 30 days following discharge. Low-risk patients were defined as those who experienced no negative endpoints. The CISNE score was more specific than the MASCC in identifying low-risk patients (98.1% vs. 54.2%), suggesting that the CISNE may be useful for hospitalists in identifying patients who may be safely discharged with oral antibiotics and close follow-up.

Limitations include possible misclassification bias from indirect assessment of symptom severity, lack of recent ECOG scores for six patients in the CISNE arm, and possible undocumented symptoms during ED evaluation required for subsequent score calculation. Additionally, most patients in this study reported mild symptoms which weighted their MASCC classification toward low-risk.

Bottom Line: The CISNE score may aid in risk-stratification of patients with chemotherapy-related febrile neutropenia presenting to the ED.

Reference: Coyne CJ, Le V, Brennan JJ, et al. Application of the MASCC and CISNE risk-stratification scores to identify low-risk febrile neutropenic patients in the emergency department. Ann Emerg Med. Published online 29 Dec 2016. doi: 10.1016/j.annemergmed.2016.11.007.
 

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.

 

Clinical Question: Does the Multinational Association for Supportive Care in Cancer (MASCC) or Clinical Index of Stable Febrile Neutropenia (CISNE) risk-stratification score better predict patient outcomes in patients presenting to emergency departments with febrile neutropenia?

Background: Risk-stratification metrics like the MASCC and CISNE identify subsets of relatively low-risk patients with febrile neutropenia after chemotherapy for treatment at home with empiric oral antibiotic therapy and close follow-up while awaiting results of infectious work-up. Prior studies have validated these tools for admitted, but not for ED, patients.

Study Design: Retrospective cohort study.

Setting: Two academic ED at National Institutes of Health–designated cancer centers.

Synopsis: Included patients (n = 230) were at least 16 years old with a documented fever of 38° C or greater related to chemotherapy and an absolute neutrophil count less than 1,000 cells/μL. MASCC and CISNE risk stratification scores were calculated based on the documentation from the ED and recent oncology clinic visits. Outcome measures included length of stay, upgrade in level of care, positive blood cultures, clinical deterioration, and death and were assessed for up to 30 days following discharge. Low-risk patients were defined as those who experienced no negative endpoints. The CISNE score was more specific than the MASCC in identifying low-risk patients (98.1% vs. 54.2%), suggesting that the CISNE may be useful for hospitalists in identifying patients who may be safely discharged with oral antibiotics and close follow-up.

Limitations include possible misclassification bias from indirect assessment of symptom severity, lack of recent ECOG scores for six patients in the CISNE arm, and possible undocumented symptoms during ED evaluation required for subsequent score calculation. Additionally, most patients in this study reported mild symptoms which weighted their MASCC classification toward low-risk.

Bottom Line: The CISNE score may aid in risk-stratification of patients with chemotherapy-related febrile neutropenia presenting to the ED.

Reference: Coyne CJ, Le V, Brennan JJ, et al. Application of the MASCC and CISNE risk-stratification scores to identify low-risk febrile neutropenic patients in the emergency department. Ann Emerg Med. Published online 29 Dec 2016. doi: 10.1016/j.annemergmed.2016.11.007.
 

Dr. Frederick is assistant clinical professor in the division of hospital Medicine, department of medicine, University of California, San Diego.