BENEFICIAL EFFECT OF ENALAPRIL ON LEFT-VENTRICULAR REMODELING IN PATIENTS WITH A SEVERE RESIDUAL STENOSIS AFTER ACUTE ANTERIOR WALL INFARCTION

Objective The present study was designed to evaluate the effects of ea rly angiotensin converting enzyme (ACE) inhibition on left ventricular enlargement in patients with anterior wall infarction following reper fusion therapy. Methods Seventy-one consecutive patients with an anter ior wall myocardial infarction were randomly allocated to enalapril (n =36) or placebo (n=35). All patients received either thrombolytic ther apy (n=46) or underwent primary coronary angioplasty (n=25). Medicatio n was started within 48 h admission to hospital and continued for 48 w eeks. The process of left ventricular remodelling was assessed with tw o-dimensional echocardiography at 3 weeks and 1 year after the acute o nset, and was related to the severity of the residual stenosis of the infarct-related artery. Results Baseline left ventricular ejection fra ction 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 yea r in control patients (P<0.001). In the enalapril-treated patients, le ft 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) a fter 1 year (P<0.001). Both at 3 weeks and after 1 year, no overall di fferences in left ventricular volumes were observed between the enalap ril and the placebo group (both ns). However, patients with a residual stenosis severity of greater than or equal to 70% in the infarct-rela ted artery (n=43) showed significant attenuation of remodelling by ena lapril (n=22) when compared to placebo (n=21). In patients on enalapri l: 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 +/- 1 6.3 ml.m(-2) in control patients (P<0.03). Also diastolic filling para meters were significantly improved in patients with greater than or eq ual to 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 dilatatio n is an early process we suggest that treatment with ACE inhibition sh ould be started as soon as possible in this group of patients.