Long-term prognosis of transient acute myocardial ischemia at rest

A medical approach to treatment was adopted in 652 patients with documented myocardial ischemia at rest during both the acute and follow-up phases. No patient underwent coronary revascularization during hospitalization and only 86 patients (13%) underwent coronary bypass surgery within 8 months from discharge. During hospitalization 13 patients died. In the remaining group (639 patients), the likelihood of death in the 10-year period after discharge was 28% for all patients and 20% for cardiac causes only. A series of factors studied during the acute stage were assessed in an effort to predict long-term outcome. The following noninvasive characteristics, listed in decreasing order of statistical significance, were found to be significant univariate predictors of survival: abnormal basal electrocardiogram, duration of coronary artery disease, previous myocardial infarction, pattern of ST-T changes during episodes of ischemia at rest, age and systemic hypertension. The average annual mortality rate for patients with T-wave changes, ST-segment elevation and ST-segment depression was 0.9, 1.8 and 3%, respectively. The Cox survival analysis identified abnormal basal electrocardiogram, duration of coronary artery disease and pattern of ST-T changes as significant, independent predictors of death. When invasive characteristics were entered in the model, number of greater than or equal to 50% narrowed coronary arteries, left ventricular ejection fraction, abnormal basal electrocardiogram and smoking habit were found to be independent and additive prognostic variables. Thus, long-term prognosis of patients with ischemia at rest is related to the severity of anatomic impairment, independent of the pattern of ST-T changes observed during the acute phase.(ABSTRACT TRUNCATED AT 250 WORDS)