Clinical course and risk stratification of myocardial infarct survivors with three-vessel disease.

Prevalence of three-vessel disease was prospectively analyzed in a series of 462 consecutive infarct survivors aged 60 years or less. Eighty-seven percent (403) of the patients were catheterized within one month of the acute event, and were followed for a mean of 43 months (range 21 to 69). Three-vessel disease was present in 96 cases (24%) and these patients form the study population. The primary goals of this study were to determine the prevalence of three-vessel disease and to identify predictors of survival and new coronary events among this subset of infarct survivors. During follow-up, 15 patients died, 17 had a recurrent nonfatal infarction, and 54 developed angina (4-year probability of each cardiac event being 0.20, 0.22, and 0.59, respectively). Cox's stepwise multivariate analysis identified the ejection fraction (EF) as the only predictor of survival (p less than 0.001). No predictors for nonfatal ischemic events were found among the independent variables considered. Patients were stratified in risk categories according to the EF. Four-year probability of survival was 1.0 in participants with EF = greater than 50% (n = 23), 0.77 for those with EF = 21% to 49% (n = 66), and 0.22 in patients with more severe left ventricular dysfunction, EF = less than 20% (n = 7). Probability of occurrence of nonfatal reinfarction or angina was similar in the three risk categories. Thus, our results indicate that a normal ejection fraction is found in 25% of infarct survivors with three-vessel disease, and that this subset of patients has a low incidence of early and intermediate range coronary events.