Predicting severe ischemic events after uncomplicated myocardial infarction by exercise testing and rest and exercise radionuclide ventriculography.

Abstract

In 183 patients with uncomplicated myocardial infarction, exercise-induced angina, ST segment depression, decrease in ejection fraction, or inadequate increase in systolic blood pressure and low exercise tolerance were significantly associated with 4-year incidence of hard ischemic events. Only the onset of both ST segment depression and a decrease in left ventricular ejection fraction with exercise was an independent predictor. ST segment depression and decrease in left ventricular ejection fraction had low sensitivity (61% and 70%) and specificity (56% and 51%) for hard ischemic events, but specificity increased to 78% when both were present. During medical therapy, 22 of 53 patients with both ST segment depression and a decrease in left ventricular ejection fraction with exercise had an ischemic event (i.e., 48.1% 4-year probability on Kaplan-Meier analysis vs 19.2% in the remaining 130 patients [p < 0.0005]). Even if no single variable, derived from exercise testing, is a highly sensitive and specific predictor, specificity increases to a clinically relevant level by combining ST segment depression and a decrease in left ventricular ejection fraction with exercise, and in this way patients with recent infarction may be selected for coronary arteriography.