Early treatment with low dose of enalapril prevents left ventricular dilatation after acute myocardial infarction

pp 529-535

Abstract

The aim of this study was to determine whether a fixed dose (10 mg/day) of enalapril (E) begun within 48 hours after the onset of acute myocardial infarction (AMI) could attenuate progressive left ventricular (LV) enlargement. We also assessed the effects of withdrawal of E on LV function and compared early versus late (45 days) treatment. To this end, 89 patients with a first AMI and LV ejection fraction (FE) < 45 % were included in a double blind study comparing E and placebo with a crossover design. Patients were random- ly assigned to sequence. A (enalapril 45 days - placebo 45 days), or B (placebo 45 days - enalapril 45 days). All pretreatment variables were similar in the two groups. Thrombolysis was administered to 26 patients (70 %) in group A and 25 patients (75 %) in group B, p >0.05. Primary end point was LV volume assessed by radio nuclide ventriculogram on admission and at 45 and 90 days. Shown below are values of LV end diastolic volume (ml, mean :t sd): group A (n: 37), EDV baseline, 40.4 (32.56); 45 days (%), 0.27 (-6.27); 90 days (%), 5.75 (-15.28). Group B (n: 33), 45 (30.57); 45 days (%), 12.73 (0.39) (p < 0.01); 90 days (%), 9,5 (-10.32). Similar changes were observed in LV systolic volume. No significant changes in EF were seen. Thus, in patients with first MI and EF < 45 %, early treatment with low doses of enalapril prevents LV dilatation. Absence of subsequent enlargement after withdrawal from enalapril probably reflects attenuation of adverse re- modeling, delayed (45 days) therapy with enalapril has no influence on LV dilatation.