Overview of Randomized Trials of Angiotensin-Converting Enzyme Inhibitors on Mortality and Morbidity in Patients With Heart Failure

Abstract

OBJECTIVE: To evaluate the effect of angiotensin-converting enzyme (ACE) inhibitors on mortality and morbidity in patients with symptomatic congestive heart failure. DATA SOURCE AND STUDY SELECTION: Data were obtained for all completed, published or unpublished, randomized, placebo-controlled trials of ACE inhibitors that were at least 8 weeks in duration and had determined total mortality by intention to treat, regardless of sample size. Trials were identified based on literature review and correspondence with investigators and pharmaceutical firms. DATA EXTRACTION: Using standard tables, data were extracted by one author and confirmed where necessary by the other author or the principal investigator of the trial. Unpublished data were obtained by direct correspondence with the principal investigator of each study or pharmaceutical firm. DATA SYNTHESIS: The data for each outcome were combined using the Yusuf-Peto adaptation of the Mantel-Haenszel method. Overall, there was a statistically significant reduction in total mortality (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.67 to 0.88; P < .001) and in the combined endpoint of mortality or hospitalization for congestive heart failure (OR, 0.65; 95% CI, 0.57 to 0.74; P < .001). Similar benefits were observed with several different ACE inhibitors, although the data were largely based on enalapril maleate, captopril, ramipril, quinapril hydrochloride, and lisinopril. Reductions for total mortality and the combined endpoint were similar for various subgroups examined (age, sex, etiology, and New York Heart Association class). However, patients with the lowest ejection fraction appeared to have the greatest benefit. The greatest effect was seen during the first 3 months, but additional benefit was observed during further treatment. The reduction in mortality was primarily due to fewer deaths from progressive heart failure (OR, 0.69; 95% CI, 0.58 to 0.83); point estimates for effects on sudden or presumed arrhythmic deaths (OR, 0.91; 95% CI, 0.73 to 1.12) and fatal myocardial infarction (OR, 0.82; 95% CI, 0.60 to 1.11) were less than 1 but were not significant. CONCLUSIONS: Total mortality and hospitalization for congestive heart failure are significantly reduced by ACE inhibitors with consistent effects in a broad range of patients.