Tolerability of enalapril in congestive heart failure

In a double-blind, randomized trial, 253 patients with heart failure (New York Heart Association functional class IV) received either enalapril (n = 127) or placebo (n = 126) in addition to their conventional therapeutic regimens (digitalis, diuretics and vasodilators other than angiotensin-converting enzyme inhibitors). Enalapril was administered in a dose of 2.5 to 40 mg/day. The placebo group was administered placebo tablets in addition to their conventional therapeutic regimen. The study was discontinued prematurely for ethical reasons because of the highly significant (p = 0.003) difference in mortality between the enalapril (n = 50) and placebo groups (n = 68). The important reduction was observed among patients dying from progressive heart failure. Follow-up ranged from 1 day to 20 months (average 188 days). The reduction in mortality was associated with general improvements in symptoms and signs of left and right ventricular heart failure, reduction of heart size, improvements in New York Heart Association classification, reduction of concurrent cardiovascular medication, and reduction in the number of hospital admissions and duration of hospitalization. The overall rate of withdrawal from the study was low and was comparable in the 2 treatment groups (16%). Induced hypotension was an intentional part of the treatment, and symptomatic hypotension was observed in 17% of treated patients vs 0% of the placebo group. Hypotension was the reason for withdrawal in 7 patients. After the initial dose of enalapril was reduced to 2.5 mg in high-risk patients, hypotension was the reason for withdrawal in only 3% of all patients. Hyperkalemia was observed exclusively among patients concurrently using potassium-sparing agents.(ABSTRACT TRUNCATED AT 250 WORDS)