Prospective evaluation comparing the effects of enalapril and losartan in left ventricular remodeling after acute myocardial infarction.

BACKGROUND

Previous studies have compared angiotensin receptor blockers and angiotensin-converting enzyme inhibitors in patients with heart failure, but there are few data about the effect of these drugs regarding left ventricular remodeling after myocardial infarction.

METHODS

Fifty-two consecutive patients with first anterior wall myocardial infarction within 24 hours of evolution were randomized to receive enalapril (as much as 20 mg; mean, 14.6 mg), or losartan (as much as 50 mg; mean, 48 mg). Left ventricular ejection fraction and ventricular volumes were analyzed in 2 serial radionuclide ventriculograpies, carried out within 4 days after the infarction (mean, 97.4 +/- 114.2 hours) and after 6 months (mean, 177.7 +/- 16.7 days). Ventriculographies were analyzed by a single blinded observer. Mainly because of the unexpected large SD values obtained, the power of the study to demonstrate equivalence between the groups was only 15.7%.

RESULTS

The differences obtained between the first and the second ventriculographies, for the enalapril and losartan groups, were: for left ventricular ejection fraction, -0.4% +/- 6.6% versus -1.1% +/- 5.9% (P =. 67; 95% CI, 2.77-4.23); for final systolic volume, 0.07 +/- 7.7 mL/m(2) versus -0.2 +/- 6.1mL/m(2) (P =. 85; 95% CI, -3.57-4.26); for final diastolic volume -0.7 +/- 12.1 mL/m(2) versus -3.6 - 9.9 mL/m(2) (P =. 34; 95% CI, -3.22-9.17).

CONCLUSION

This study, although underpowered, suggests that neither enalapril nor losartan was superior as compared with each other for left ventricular remodeling after myocardial infarction; however, powerful evidence of equivalence was not provided.