Comparison of enalapril versus captopril on left ventricular function and survival three months after acute myocardial infarction (the “practical” Study)

Abstract Left ventricular (LV) function and survival can be improved with captopril when initiated later than 24 hours after acute myocardial infarction. Animal studies suggest additional benefits may be obtained with earlier initiation of angiotensinconverting enzyme (ACE) inhibitors. The effects on LV function of captopril and enalapril initiated within 24 hours of myocardial infarction were studied. Two hundred twenty-five patients with acute myocardial infarction were enrolled within 24 hours of the onset of chest pain. They were randomized to receive either captopril 25 mg three times daily, enalapril 5 mg three times daily, or placebo. LV ejection fraction (EF) and volumes were measured by radionuclide ventriculography at baseline during treatment and at 3 months after a 3-day withdrawal from therapy. The ACE inhibitor group had a significant increase in EF (45 ± 1 to 47 ± 1%; p = 0.005) and significantly attenuated LV dilatation compared with results in the placebo group (175 ± 6 to 189 ± 7 ml in the placebo group vs 168 ± 4 to 172 ± 4 ml in the ACE inhibitor group; p = 0.051 for LV end-diastolic volume; and 99 ± 6 to 108 ± 7 ml in the placebo group vs 94 ± 3 to 94 ± 4 ml; p = 0.026 for LV end-systolic volume). The beneficial effects of ACE inhibitor therapy on LV function were observed irrespective of the degree of initial LV dysfunction and were comparable in both the captopril and enalapril groups. Survival at 90 days and 12 months was significantly improved in the enalapril group (7 placebo, 9 captopril, 1 enalapril [p = 0.038] and 12 placebo, 10 captopril, 2 enalapril [p = 0.022]; deaths at 90 days and 12 months, respectively). Immediate administration of captopril and enalapril improved LV function and prevented LV dilatation after acute myocardial infarction. The benefit was similar with both ACE inhibitors and was in excess of the benefits of optimal conventional therapy.