Silent myocardial ischemia in asymptomatic survivors of unrecognized myocardial infarction and matched controls

Although silent myocardial ischemia (SI) occurs frequently in patients with angina and is of prognostic significance, little is known of its occurrence in other subgroups. We assessed the incidence of SI in offspring of Framingham Heart Study (FHS) patients following unrecognized myocardial infarction (UMI) and in controls without MI but who were matched for age, sex, hypertension, diabetes, smoking, and total cholesterol at entry into the FHS. Of the 20 UMI patients, six had died and one with left bundle branch block was excluded. The remaining 13 UMI patients and 26 control patients underwent 24-hour ambulatory electrocardiographic monitoring (AECG) for SI. Two patients (one from each group) with angina were excluded from the AECG analysis. Only two (15.4%) of the UMI patients and two (7.7%) of the control patients had any AECG evidence of SI. These preliminary results suggest that routine monitoring for SI is not indicated in asymptomatic long-term survivors of UMI or in asymptomatic patients without prior MI but with otherwise similar risk profiles.