Objective: The present study was designed to evaluate the effects of early angiotensin converting enzyme (ACE) inhibition on left ventricular enlargement in patients with anterior wall infarction following reperfusion therapy.
Methods: Seventy-one consecutive patients with an anterior wall myocardial infarction were randomly allocated to enalapril (n = 36) or placebo (n = 35). All patients received either thrombolytic therapy (n = 46) or underwent primary coronary angioplasty (n = 25). Medication was started within 48 h admission to hospital and continued for 48 weeks. The process of left ventricular remodelling was assessed with two-dimensional echocardiography at 3 weeks and 1 year after the acute onset, and was related to the severity of the residual stenosis of the infarct-related artery.
Results: Baseline left ventricular ejection fraction was 39.2% +/- 8.7%. During the study period left ventricular end-diastolic volume index increased from 48.2 +/- 9.9 ml.m-2 to 54.6 +/- 12.2 ml.m-2 at 3 weeks, and to 59.4 +/- 17.0 ml.m-2 after 1 year I control patients (P < 0.001). In the enalapril-treated patients, left ventricular end-diastolic volume index increased from 50.0 +/- 16.1 to 57.7 +/- 19.3 ml.m-2 at 3 weeks, and to 61.9 +/- 22.7 ml.m-2 after 1 year (P < 0.001). Both at 3 weeks and after 1 year, no overall differences in left ventricular volumes were observed between the enalapril and the placebo group (both ns). However, patients with a residual stenosis severity of > or = 70% in the infarct-related artery (n = 43) showed significant attenuation of remodelling by enalapril (n = 22) when compared to placebo (n = 21). In patients on enalapril, left ventricular end-diastolic volume index increased from 47.0 +/- 13.0 to 53.7 +/- 17.7 ml.m-2 compared to 48.0 +/- 9.6 to 60.3 +/- 16.3 ml.m-2 in control patients (P < 0.03). Also diastolic filling parameters were significantly improved in patients with > or = 70% residual stenosis.
Conclusion: In patients with an anterior wall infarction and a severe residual infarct-related coronary artery stenosis following reperfusion, treatment with enalapril prevents the process of left ventricular remodelling. As left ventricular dilatation is an early process we suggest that treatment with ACE inhibition should be started as soon as possible in this group of patients.