PROGNOSTIC SIGNIFICANCE OF SERIAL EXERCISE TESTING AFTER MYOCARDIAL-INFARCTION

Serial treadmill exercise testing (mean 5.5 tests/patients) was used to evaluate the prognosis of 200 males (mean age 53 yr) without clinical heart failure or unstable angina pectoris 3 weeks after acute myocardial infarction (MI). Exercise-induced ischemic ST-segment depression ≥0.2 mV 3 weeks after MI was significantly more prevalent in patients with subsequent cardiac arrest (100%) or coronary artery bypass graft surgery (64%) than in patients without subsequent events within 2 years of infarction (35%) (p<0.05). Exercise-induced ventricular arrhythmia on multiple tests 5-25 weeks after MI was more prevalent in patients with recurrent myocardial infarction (90%) than in patients without subsequent events (47%) (p<0.001). By contrast, exercise-induced ventricular arrhythmia on a single test at 3 weeks was a less powerful predictor of subsequent cardiac events. Exercise-induced ischemia 3 weeks after MI predicted early fatal events, while ventricular arrhythmia on serial testing predicted later nonfatal events.