Low-dose enalapril in severe chronic heart failure

In a 3-month prospective, single-blind, controlled trial, 38 patients in New York Heart Association functional class III-IV were assigned to group E (n = 19): enalapril 5 mg/day in addition to the previous therapy with digitalis and diuretics, or group C (n = 19): continuation of the previous therapy. In group E, 79% of the patients improved by at least one NYHA functional class after 3 months. In group C, the functional class did not change and four patients died. The echocardiographically determined end-diastolic diameter of the left ventricle decreased in group E from 72 +/- 8 mm to 63 +/- 6 mm (p less than 0.001), and the scintigraphically determined ejection fraction of the left ventricle increased from 33 +/- 18% to 40 +/- 19% (p less than 0.002). In contrast, no significant change was found in group C. Plasma-renin activity increased in group E from 8.2 +/- 1.8 ng/ml h to 29.7 +/- 14 ng/ml h (p less than 0.001), and plasma aldosterone decreased from 47.7 +/- 7.6 ng/dl to 19.9 +/- 4.8 ng/dl (p less than 0.01). In group C no significant change occurred. Comparing the actual changes (deltas) of the NYHA functional class (p less than 0.02), end-diastolic diameter and ejection fraction of the left ventricle, plasma-renin activity, and plasma aldosterone (p less than 0.0001), a significant difference between the two groups was found. Thus, low-dose enalapril resulted in a significant improvement of the NYHA functional class in patients with severe chronic heart failure, accompanied by an improvement in left ventricular function and a decrease in secondary aldosteronism.