Prognostic value of exercise testing in a cohort of patients followed for 15 years after acute myocardial infarction

Aims: To study the long-term prognostic information obtained from an exercise test following an acute myocardial infarction. Methods: Between 1979 and 1983, 1773 consecutive patients were admitted to Glostrup County Hospital with an acute myocardial infarction. Of 1430 patients who were alive after 3 weeks, 718 performed an exercise test. Survival data were available after 15 years for all patients. Results: Participation in an exercise test was associated with a risk reduction of death of 56% (95% confidence interval, 49-65%) when adjusting for known differences between the groups. Among patients who performed the test, most indicators of ischaemia were without prognostic information. Exercise tolerance, expressed in metabolic equivalents, was the best predictor of future mortality (relative risk 0.86 for an increase of one metabolic equivalent (0·80-0·92)). Only ST-segment depression of 2 mm or more could identify a population with an increased risk of death (relative risk 1·45 (1·08-1·95)). Conclusion: Patients who perform an exercise test after acute myocardial infarction are a low risk population compared to those who do not perform it. The detection of ischaemia during the test is of marginal prognostic value. Exercise capacity is the most powerful predictor of death that can be obtained from the test.