EFFECT OF LONG-TERM ENALAPRIL THERAPY ON CARDIOPULMONARY EXERCISE PERFORMANCE IN MEN WITH MILD HEART-FAILURE AND PREVIOUS MYOCARDIAL-INFARCTION

Forty-one men with documented myocardial infarction > 6 months previously were randomized to long-term (48 weeks) therapy with placebo or enalapril on a double-blind basis. All patients were receiving concurrent therapy with digitalis and a diuretic drug for symptomatic heart failure (functional class II or III). The mean age was 64 +/- 7.3 years and no patient suffered from exertional chest pain. Patients underwent maximal cardiopulmonary exercise testing to exhaustion on an ergometer cycle nine times over the course of 48 weeks. Gas exchange data were collected on a breath by breath basis with use of a continuous ramp protocol. In the placebo group (n = 21), the mean (+/- SD) peak oxygen consumption (VO2) at baseline was 18.8 +/- 5.2 versus 18.5 +/- 5.5 ml/kg per min at 48 weeks (-1.4%, p = NS). In the enalapril group (n = 20), the corresponding values were 18.1 +/- 3.1 versus 18.3 +/- 2.6 ml/kg per min (+2.8%, p = NS). The mean VO2 at the anaerobic threshold for the placebo group at baseline study was 13.1 +/- 3.5 versus 12.8 +/- 2.1 ml/kg per min at 48 weeks (-2.2%, p = NS). The corresponding values for the enalapril group were 11.8 +/- 2.3 versus 11.8 +/- 2.4 ml/kg per min (+1.4%, p = NS). The mean total exercise duration in the placebo group at baseline study was 589 +/- 153 versus 620 +/- 181 s at 48 weeks (+5.4%, p = NS). The corresponding values for the enalapril group were 614 +/- 119 versus 632 +/- 120 s (+3.5%, p = NS). There were no significant intergroup differences at any time with regard to peak VO2, VO2 at the anaerobic threshold or exercise duration. Long-term angiotensin-converting enzyme inhibition with enalapril in men with mild heart failure after myocardial infarction was not associated with significant improvement in peak or submaximal cardiopulmonary exercise performance.