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Patients with a pulmonary artery pressure/cardiac output slope greater than 3 mm Hg/L/min on cardiopulmonary exercise tests have more than double the risk of cardiovascular hospitalization and all-cause mortality, according to a prospective study of 714 subjects with exertional dyspnea but preserved ejection fractions.
The findings “suggest that across a wide range of individuals with chronic dyspnea, exercise can unmask abnormal pulmonary vascular responses that in turn bear significant clinical implications. These findings, coupled with a growing body of work ... suggest that reintroduction of an exercise based definition of [pulmonary hypertension (PH)] in PH guidelines” – using the pulmonary artery pressure/cardiac output slope – “merits consideration,” wrote Jennifer Ho, MD, a heart failure and transplantation cardiologist at Massachusetts General Hospital, Boston, and colleagues (J Am Coll Cardiol. 2020 Jan 7;75[1]:17-26. doi: 10.1016/j.jacc.2019.10.048).
A new definition takes hold
The slope captures the steepness of pulmonary artery pressure increase as cardiac output goes up, giving a measure of overall pulmonary resistance. A value above 3 mm Hg/L/min means that pulmonary artery pressure (PAP) is too high for a given cardiac output (CO). The slope “is preferable to using a single absolute cut point value for exercise PAP” to define exercise pulmonary hypertension.“ Indeed, we confirm that in the absence of elevated PAP/CO, an absolute exercise PAP [above] 30 mm Hg” – the definition of exercise-induced pulmonary hypertension in years past – “does not portend worse outcomes,” Dr. Ho and her team noted.
In an accompanying editorial titled, “Exercise Pulmonary Hypertension Is Back,” Marius Hoeper, MD, a senior physician in the department of respiratory medicine at Hannover (Germany) Medical School, explained that the findings likely signal the revival of exercise pulmonary hypertension as a useful clinical concept (J Am Coll Cardiol. 2020 Jan 7;75[1]:27-8. doi: 10.1016/j.jacc.2019.11.010).
The standalone 30 mm Hg cut point was largely abandoned about a decade ago when it was realized that pressures above that mark were “not necessarily abnormal in certain subjects, for instance in athletes or elderly individuals,” he said.
But it’s become clear in recent years, and now confirmed by Dr. Ho and her team, that what matters is not the stand-alone measurement, but it’s relationship to cardiac output. “There is now sufficient evidence to define exercise PH by an abnormal [mean]PAP/CO slope [above] 3 mm Hg/L/min,” Dr. Hoeper said.
Abnormal slopes in over 40%
Each subject in the Massachusetts General study had an average of 10 paired PAP and CO measurements taken by invasive hemodynamic monitoring, including pulmonary artery catheterization via the internal jugular vein, while they road a stationary bicycle. The measurements were used to calculate the PAP/CO slope. A slope greater than 3 mm Hg/L/min was defined as abnormal based on previous research.
Results of the one-time assessment were correlated with the study’s primary outcome – cardiovascular hospitalization or all-cause death – over a mean follow up of 3.7 years. Subjects were 57 years old, on average, and 59% were women; just 2% had a previous diagnosis of pulmonary hypertension. Overall, 41% of the subjects had abnormal PAP/CO slopes, 26% had abnormal slopes without resting pulmonary hypertension, and 208 subjects (29%) met the primary outcome.
After adjustments for age, sex, and cardiopulmonary comorbidities, abnormal slopes more than doubled the risk of the primary outcome (hazard ratio [HR] 2.03; 95% confidence interval [CI]: 1.48-2.78; P less than .001). The risk remained elevated even in the absence of resting pulmonary hypertension (HR 1.75, 95% CI 1.21-2.54, P = .003), and in people with only mildly elevated resting PAPs of 21-29 mm Hg.
Older people were more likely to have abnormally elevated slopes, as well as were those with cardiopulmonary comorbidities, lower exercise tolerance, lower peak oxygen uptake, and more severely impaired right ventricular function. Diabetes, prior heart failure, chronic obstructive pulmonary disease, and interstitial lung disease were more prevalent in the elevated slope group, and their median N-terminal pro–B type natriuretic peptide level was 154 pg/mL, versus 52 pg/mL among people with normal slopes.
A simpler test is needed
In his editorial, Dr. Hoeper noted that diagnosing exercise PH by elevated slope “will occasionally help physicians and patients to better understand exertional dyspnea and to detect early pulmonary vascular disease in patients at risk,” but for the most part, the new definition “will have little immediate [effect] on clinical practice, as evidence-based treatments for this condition are not yet available.”
Even so, “having a globally accepted gold standard” for exercise PH based on the PAP/CO slope might well spur development of “simpler, noninvasive” ways to measure it so it can be used outside of specialty settings.
Dr. Ho and her team agreed. “These findings should prompt additional work using less invasive measurement modalities such as exercise echocardiography to evaluate” exercise PAP/CO slopes, they said.
The work was funded by the National Institutes of Health, Gilead Sciences, the American Heart Association, and the Massachusetts General Hospital Heart Failure Research Innovation Fund. The investigators had no relevant disclosures. Dr. Hoeper reported lecture and consultation fees from Actelion, Bayer, Merck Sharp and Dohme, and Pfizer.
SOURCE: Ho JE et al., J Am Coll Cardiol. 2020 Jan 7;75(1):17-26. doi: 10.1016/j.jacc.2019.10.048.
Patients with a pulmonary artery pressure/cardiac output slope greater than 3 mm Hg/L/min on cardiopulmonary exercise tests have more than double the risk of cardiovascular hospitalization and all-cause mortality, according to a prospective study of 714 subjects with exertional dyspnea but preserved ejection fractions.
The findings “suggest that across a wide range of individuals with chronic dyspnea, exercise can unmask abnormal pulmonary vascular responses that in turn bear significant clinical implications. These findings, coupled with a growing body of work ... suggest that reintroduction of an exercise based definition of [pulmonary hypertension (PH)] in PH guidelines” – using the pulmonary artery pressure/cardiac output slope – “merits consideration,” wrote Jennifer Ho, MD, a heart failure and transplantation cardiologist at Massachusetts General Hospital, Boston, and colleagues (J Am Coll Cardiol. 2020 Jan 7;75[1]:17-26. doi: 10.1016/j.jacc.2019.10.048).
A new definition takes hold
The slope captures the steepness of pulmonary artery pressure increase as cardiac output goes up, giving a measure of overall pulmonary resistance. A value above 3 mm Hg/L/min means that pulmonary artery pressure (PAP) is too high for a given cardiac output (CO). The slope “is preferable to using a single absolute cut point value for exercise PAP” to define exercise pulmonary hypertension.“ Indeed, we confirm that in the absence of elevated PAP/CO, an absolute exercise PAP [above] 30 mm Hg” – the definition of exercise-induced pulmonary hypertension in years past – “does not portend worse outcomes,” Dr. Ho and her team noted.
In an accompanying editorial titled, “Exercise Pulmonary Hypertension Is Back,” Marius Hoeper, MD, a senior physician in the department of respiratory medicine at Hannover (Germany) Medical School, explained that the findings likely signal the revival of exercise pulmonary hypertension as a useful clinical concept (J Am Coll Cardiol. 2020 Jan 7;75[1]:27-8. doi: 10.1016/j.jacc.2019.11.010).
The standalone 30 mm Hg cut point was largely abandoned about a decade ago when it was realized that pressures above that mark were “not necessarily abnormal in certain subjects, for instance in athletes or elderly individuals,” he said.
But it’s become clear in recent years, and now confirmed by Dr. Ho and her team, that what matters is not the stand-alone measurement, but it’s relationship to cardiac output. “There is now sufficient evidence to define exercise PH by an abnormal [mean]PAP/CO slope [above] 3 mm Hg/L/min,” Dr. Hoeper said.
Abnormal slopes in over 40%
Each subject in the Massachusetts General study had an average of 10 paired PAP and CO measurements taken by invasive hemodynamic monitoring, including pulmonary artery catheterization via the internal jugular vein, while they road a stationary bicycle. The measurements were used to calculate the PAP/CO slope. A slope greater than 3 mm Hg/L/min was defined as abnormal based on previous research.
Results of the one-time assessment were correlated with the study’s primary outcome – cardiovascular hospitalization or all-cause death – over a mean follow up of 3.7 years. Subjects were 57 years old, on average, and 59% were women; just 2% had a previous diagnosis of pulmonary hypertension. Overall, 41% of the subjects had abnormal PAP/CO slopes, 26% had abnormal slopes without resting pulmonary hypertension, and 208 subjects (29%) met the primary outcome.
After adjustments for age, sex, and cardiopulmonary comorbidities, abnormal slopes more than doubled the risk of the primary outcome (hazard ratio [HR] 2.03; 95% confidence interval [CI]: 1.48-2.78; P less than .001). The risk remained elevated even in the absence of resting pulmonary hypertension (HR 1.75, 95% CI 1.21-2.54, P = .003), and in people with only mildly elevated resting PAPs of 21-29 mm Hg.
Older people were more likely to have abnormally elevated slopes, as well as were those with cardiopulmonary comorbidities, lower exercise tolerance, lower peak oxygen uptake, and more severely impaired right ventricular function. Diabetes, prior heart failure, chronic obstructive pulmonary disease, and interstitial lung disease were more prevalent in the elevated slope group, and their median N-terminal pro–B type natriuretic peptide level was 154 pg/mL, versus 52 pg/mL among people with normal slopes.
A simpler test is needed
In his editorial, Dr. Hoeper noted that diagnosing exercise PH by elevated slope “will occasionally help physicians and patients to better understand exertional dyspnea and to detect early pulmonary vascular disease in patients at risk,” but for the most part, the new definition “will have little immediate [effect] on clinical practice, as evidence-based treatments for this condition are not yet available.”
Even so, “having a globally accepted gold standard” for exercise PH based on the PAP/CO slope might well spur development of “simpler, noninvasive” ways to measure it so it can be used outside of specialty settings.
Dr. Ho and her team agreed. “These findings should prompt additional work using less invasive measurement modalities such as exercise echocardiography to evaluate” exercise PAP/CO slopes, they said.
The work was funded by the National Institutes of Health, Gilead Sciences, the American Heart Association, and the Massachusetts General Hospital Heart Failure Research Innovation Fund. The investigators had no relevant disclosures. Dr. Hoeper reported lecture and consultation fees from Actelion, Bayer, Merck Sharp and Dohme, and Pfizer.
SOURCE: Ho JE et al., J Am Coll Cardiol. 2020 Jan 7;75(1):17-26. doi: 10.1016/j.jacc.2019.10.048.
Patients with a pulmonary artery pressure/cardiac output slope greater than 3 mm Hg/L/min on cardiopulmonary exercise tests have more than double the risk of cardiovascular hospitalization and all-cause mortality, according to a prospective study of 714 subjects with exertional dyspnea but preserved ejection fractions.
The findings “suggest that across a wide range of individuals with chronic dyspnea, exercise can unmask abnormal pulmonary vascular responses that in turn bear significant clinical implications. These findings, coupled with a growing body of work ... suggest that reintroduction of an exercise based definition of [pulmonary hypertension (PH)] in PH guidelines” – using the pulmonary artery pressure/cardiac output slope – “merits consideration,” wrote Jennifer Ho, MD, a heart failure and transplantation cardiologist at Massachusetts General Hospital, Boston, and colleagues (J Am Coll Cardiol. 2020 Jan 7;75[1]:17-26. doi: 10.1016/j.jacc.2019.10.048).
A new definition takes hold
The slope captures the steepness of pulmonary artery pressure increase as cardiac output goes up, giving a measure of overall pulmonary resistance. A value above 3 mm Hg/L/min means that pulmonary artery pressure (PAP) is too high for a given cardiac output (CO). The slope “is preferable to using a single absolute cut point value for exercise PAP” to define exercise pulmonary hypertension.“ Indeed, we confirm that in the absence of elevated PAP/CO, an absolute exercise PAP [above] 30 mm Hg” – the definition of exercise-induced pulmonary hypertension in years past – “does not portend worse outcomes,” Dr. Ho and her team noted.
In an accompanying editorial titled, “Exercise Pulmonary Hypertension Is Back,” Marius Hoeper, MD, a senior physician in the department of respiratory medicine at Hannover (Germany) Medical School, explained that the findings likely signal the revival of exercise pulmonary hypertension as a useful clinical concept (J Am Coll Cardiol. 2020 Jan 7;75[1]:27-8. doi: 10.1016/j.jacc.2019.11.010).
The standalone 30 mm Hg cut point was largely abandoned about a decade ago when it was realized that pressures above that mark were “not necessarily abnormal in certain subjects, for instance in athletes or elderly individuals,” he said.
But it’s become clear in recent years, and now confirmed by Dr. Ho and her team, that what matters is not the stand-alone measurement, but it’s relationship to cardiac output. “There is now sufficient evidence to define exercise PH by an abnormal [mean]PAP/CO slope [above] 3 mm Hg/L/min,” Dr. Hoeper said.
Abnormal slopes in over 40%
Each subject in the Massachusetts General study had an average of 10 paired PAP and CO measurements taken by invasive hemodynamic monitoring, including pulmonary artery catheterization via the internal jugular vein, while they road a stationary bicycle. The measurements were used to calculate the PAP/CO slope. A slope greater than 3 mm Hg/L/min was defined as abnormal based on previous research.
Results of the one-time assessment were correlated with the study’s primary outcome – cardiovascular hospitalization or all-cause death – over a mean follow up of 3.7 years. Subjects were 57 years old, on average, and 59% were women; just 2% had a previous diagnosis of pulmonary hypertension. Overall, 41% of the subjects had abnormal PAP/CO slopes, 26% had abnormal slopes without resting pulmonary hypertension, and 208 subjects (29%) met the primary outcome.
After adjustments for age, sex, and cardiopulmonary comorbidities, abnormal slopes more than doubled the risk of the primary outcome (hazard ratio [HR] 2.03; 95% confidence interval [CI]: 1.48-2.78; P less than .001). The risk remained elevated even in the absence of resting pulmonary hypertension (HR 1.75, 95% CI 1.21-2.54, P = .003), and in people with only mildly elevated resting PAPs of 21-29 mm Hg.
Older people were more likely to have abnormally elevated slopes, as well as were those with cardiopulmonary comorbidities, lower exercise tolerance, lower peak oxygen uptake, and more severely impaired right ventricular function. Diabetes, prior heart failure, chronic obstructive pulmonary disease, and interstitial lung disease were more prevalent in the elevated slope group, and their median N-terminal pro–B type natriuretic peptide level was 154 pg/mL, versus 52 pg/mL among people with normal slopes.
A simpler test is needed
In his editorial, Dr. Hoeper noted that diagnosing exercise PH by elevated slope “will occasionally help physicians and patients to better understand exertional dyspnea and to detect early pulmonary vascular disease in patients at risk,” but for the most part, the new definition “will have little immediate [effect] on clinical practice, as evidence-based treatments for this condition are not yet available.”
Even so, “having a globally accepted gold standard” for exercise PH based on the PAP/CO slope might well spur development of “simpler, noninvasive” ways to measure it so it can be used outside of specialty settings.
Dr. Ho and her team agreed. “These findings should prompt additional work using less invasive measurement modalities such as exercise echocardiography to evaluate” exercise PAP/CO slopes, they said.
The work was funded by the National Institutes of Health, Gilead Sciences, the American Heart Association, and the Massachusetts General Hospital Heart Failure Research Innovation Fund. The investigators had no relevant disclosures. Dr. Hoeper reported lecture and consultation fees from Actelion, Bayer, Merck Sharp and Dohme, and Pfizer.
SOURCE: Ho JE et al., J Am Coll Cardiol. 2020 Jan 7;75(1):17-26. doi: 10.1016/j.jacc.2019.10.048.
FROM THE JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
