Treatment of Chronic Congestive Heart Failure with Captopril, an Oral Inhibitor of Angiotensin-Converting Enzyme

Abstract
The renin-angiotensin system is thought to maintain elevated systemic vascular resistance in heart failure. The hemodynamic effects of captopril (SQ 14225), an oral inhibitor of angiotensin-converting enzyme, were measured in 10 patients with stable congestive heart failure poorly controlled by digitalis and diuretics. At single daily doses of 25 to 150 mg, the cardiac index rose from 1.75±0.18 to 2.27±0.39 (mean ± S.D.) liters per minute per square meter (P5 (P<0.001), and mean arterial pressure fell from 83.7±7.0 to 70.3±9.9 mm Hg (P<0.001) (mean ± S.D.). Heart rate did not change appreciably. Hemodynamic alterations peaked at 90 minutes and persisted for three to four hours. Control plasma renin activity ranged from 1.1 to 7.3 ng per milliliter per hour and did not correlate with changes in hemodynamic values. Three patients on long-term treatment maintained clinical improvement. Although its mechanism of action has not been completely elucidated, captopril may prove useful in the treatment of chronic congestive heart failure. (N Engl J Med 301:117–121, 1979)