Plasma angiotensin-converting enzyme activity and left ventricular dilation after myocardial infarction

Left ventricular dilation after acute myocardial infarction (MI) is mainly determined by infarct size. In addition, this detrimental structural adaptation seems to be augmented in patients with the ACE DD genotype. The ACE DD genotype is associated with increased ACE activity. The aim of the present study was to evaluate whether ACE activity per se may carry prognostic significance for subsequent left ventricular dilation as assessed by echocardiography during 1-year follow-up after acute MI.

Left ventricular end-systolic and end-diastolic volume indexes were assessed by two-dimensional echocardiography. In 102 consecutive patients, plasma ACE activity was determined 3.7 +/- 0.1 hours after the onset of MI. In 64 of these patients, left ventricular volume indexes obtained at baseline and 1 year after MI were used for the present analysis. Patients were divided ino a group having low ACE activity (< or = IU/L, n = 15) and a group having high ACE activity (> 12 IU/L, n = 49). Infarct size was a significant predictor of the increase in left ventricular volume indexes (P = .0001) in these patients. Multivariate regression analysis, after correction for infarct size, demonstrated that elevated plasma ACE activity is a significant predictor of the increase in left ventricular end-diastolic and end-systolic volume indexes (P = .0006 and P = .02, respectively) 1 year after MI.

Elevated plasma ACE activity determined soon after the onset of MI may be a significant predictor of the development of left ventricular dilation and may identify patients at risk.