Study Questions Beta-Blockers for Some with Heart Failure
Diastolic versus systolic definition misleading and may lead therapy down wrong path
MONDAY, Nov. 6 (HealthDay News) -- Patients with heart failure and a preserved ejection fraction have reduced vasodilator and cardiac output reserve during exercise, which may not be due entirely to impaired diastolic function, according to a report published online Nov. 6 in Circulation: Journal of the American Heart Association. The findings suggest that beta-blockers may not be the best treatment for patients with "diastolic" heart failure, the authors say.
David A. Kass, M.D., of the Johns Hopkins Medical Institutions in Baltimore, and colleagues studied 17 patients with heart failure with preserved ejection fraction (HFpEF) and 19 matched controls who did not have heart failure but did have left ventricular hypertrophy, hypertension and other characteristics similar to the heart failure patients, such as obesity and diabetes. The patients underwent maximal-effort upright cycle ergometry to determine cardiovascular function during rest and exercise.
While both groups had similar cardiovascular function at rest and limited exercise capacity, those in the HFpEF group had a mean exercise duration of 180 seconds versus 455 seconds for the control group, and peak oxygen consumption of 9.0 mL/kg/min versus 14.4 mL/kg/min for the control group. The authors conclude that greater understanding of all facets of heart disease is needed as there are increasing numbers of heart failure patients who have apparently normal heart pumping.
"Although diastolic dysfunction occurs in HFpEF, the present data suggest that other factors such as heart rate and vasodilator reserve also play a role in exertional symptoms. These abnormalities may deserve equal attention in efforts to develop more effective treatments for this disorder," the authors write.