Effect of enalapril on survival in patients with reduced left ventricular ejection fractions and congestive heart failure

N Engl J Med. 1991 Aug 1;325(5):293-302. doi: 10.1056/NEJM199108013250501.


Background: Patients with congestive heart failure have a high mortality rate and are also hospitalized frequently. We studied the effect of an angiotensin-converting-enzyme inhibitor, enalapril, on mortality and hospitalization in patients with chronic heart failure and ejection fractions less than or equal to 0.35.

Methods: Patients receiving conventional treatment for heart failure were randomly assigned to receive either placebo (n = 1284) or enalapril (n = 1285) at doses of 2.5 to 20 mg per day in a double-bind trial. Approximately 90 percent of the patients were in New York Heart Association functional classes II and III. The follow-up averaged 41.4 months.

Results: There were 510 deaths in the placebo group (39.7 percent), as compared with 452 in the enalapril group (35.2 percent) (reduction in risk, 16 percent; 95 percent confidence interval, 5 to 26 percent; P = 0.0036). Although reductions in mortality were observed in several categories of cardiac deaths, the largest reduction occurred among the deaths attributed to progressive heart failure (251 in the placebo group vs. 209 in the enalapril group; reduction in risk, 22 percent; 95 percent confidence interval, 6 to 35 percent). There was little apparent effect of treatment on deaths classified as due to arrhythmia without pump failure. Fewer patients died or were hospitalized for worsening heart failure (736 in the placebo group and 613 in the enalapril group; risk reduction, 26 percent; 95 percent confidence interval, 18 to 34 percent; P less than 0.0001).

Conclusions: The addition of enalapril to conventional therapy significantly reduced mortality and hospitalizations for heart failure in patients with chronic congestive heart failure and reduced ejection fractions.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blood Pressure / drug effects
  • Cause of Death
  • Chronic Disease
  • Double-Blind Method
  • Electrolytes / blood
  • Enalapril / adverse effects
  • Enalapril / therapeutic use*
  • Female
  • Follow-Up Studies
  • Heart Failure / drug therapy*
  • Heart Failure / mortality
  • Heart Failure / physiopathology
  • Hospitalization
  • Humans
  • Kidney / drug effects
  • Male
  • Middle Aged
  • Patient Compliance
  • Stroke Volume*
  • Survival Rate


  • Electrolytes
  • Enalapril