Long-term prognosis of patients with silent ischemia, symptomatic ischemia and without ischemia after acute myocardial infarction

The prognosis of 55 patients with silent ischemia (group I: asymptomatic ST segment depression of greater than or equal to 0.1 mV on symptom-limited ergometer exercise) was compared with that of 25 patients with angina and ST depression (group II), 22 patients with angina but without ST depression (group III) and 94 patients without angina and without ST depression (group IV) on ergometer testing in the first post-infarction month. Patients for whom PTCA or coronary artery bypass graft surgery was planned for the next months following discharge were excluded. Groups were well matched in terms of age, sex, diabetes, non-Q-wave infarctions and global left ventricular function, but groups I and II had more inferior wall infarctions (76% and 68% respectively) than groups III and IV (18% and 34%, p less than 0.0001). After a mean follow-up time of between 26 and 33 months 11% in group I, 16% in group II, 14% in group III, but only 6% in group IV had died from cardiac disease or reinfarcted (p = 0.06). Using Cox's model, the Killip index, presence of non-Q-wave infarction, maximal ST depression on ergometer exercise and global left ventricular ejection fraction were found to be important prognostic variables affecting reinfarction-free survival, whilst angina was not. Results suggest that the presence or absence of angina as an isolated symptom is not of prognostic important after acute myocardial infarction, in comparison with objectively determinable parameters.