PHYSICAL WORKING CAPACITY AFTER ACUTE MYOCARDIAL-INFARCTION IN PATIENTS WITH LOW EJECTION FRACTION AND EFFECT OF CAPTOPRIL

Previous studies after acute myocardial infarction (AMI) have reported conflicting results on the effects of angiotensin-converting enzyme i nhibition on physical working capacity. In an effort to provide more i nsight into this subject, we examined the effects of captopril on work ing capacity of patients who had low ejection fractions but no congest ive heart failure after AMI. One hundred sixty-six participants were r ecruited from 5 centers after randomization to either captopril or pla cebo for the Survival and Ventricular Enlargement study, Upright cycle ergometer tests were performed with continuous measurements of respir atory gases at 4, 12, and 24 months after AMI. Our study concurs with 2 of 3 previous post-AMI studies and supports the conclusion that work ing capacity is not affected by angiotensin-converting enzyme inhibiti on at 4 or 12 months after AMI in patients without congestive heart fa ilure. In addition, no significant effect of captopril was noted at 24 months after AMI. Peak oxygen uptake tended to decrease between 12 an d 24 months in the placebo group by an average (+/- SD) of -22 +/- 322 ml/min (n = 66), but to increase in the captopril group (+62 +/- 289, n = 57), a difference that was significant (Mann-Whitney chi-square, p = 0.02). This post-hoc observation suggests that a late beneficial e ffect may have been masked by inadequate study duration. Known benefit s of captopril appear not to include an increase in working capacity w ithin the first 24 months after AMI.