Prognostic value of a single exercise test 3 weeks after uncomplicated myocardial infarction.

Abstract

The prognostic value of exercise testing was assessed in 195 men, mean age 54 ± 8 years, 3 weeks after uncomplicated myocardial infarction.In the first 82 men, effort was terminated at a heart rate of 130 beats/min in the absence of limiting symptoms, exertional hypotension or ventricular tachycardia.In the last 113 men, heart rate was not used as an end point.No complications of exercise testing were noted.From 13 clinical and treadmill test characteristics, a stepwise multiple logistic regression program identified exercise-induced ST-segment depression (ST;) 0.2 mV, angina pectoris and maximal work load < 4 multiples of resting energy expenditure (mets) as "risk factors" predictive of combined medical and surgical events (myocardial infarction, sudden death, cardiac arrest and coronary artery bypass surgery) in a subset of 92 patients followed 2 years or more.Clinical characteristics and exercise-induced ventricular ectopic activity were not predictive of such events.Life-table analysis in the entire population of 195 men confirmed the in- creased probability of combined medical and surgical events in patients with one or more "risk factors."For medical events alone, STI 0.2 mV and maximal work load < 4 mets were predictive, whereas angina pec- toris was not.STI > 0.2 mV and exercise-induced angina pectoris were predictive of surgical events.We conclude that patients without evidence of congestive heart failure 3 weeks after uncomplicated myocardial infarction can safely underg6 symptom-limited exercise testing.Valuable prognostic information is gained that is independent of selected clinical characteristics.IDENTIFICATION of patients soon after myocar- dial infarction who are at relatively high risk for sub- sequent cardiac events offers two major benefits.High-risk patients could be identified for more aggressive medical or surgical therapy to reduce their morbidity and mortality.Patients at low risk could be spared needless invasive studies and unwarranted restriction of their physical activities.Routine clinical methods are sufficient to identify certain subgroups of patients at increased risk for sub-