Exercise, depression, and mortality after myocardial infarction in the ENRICHD trial

The large and well-characterized population of acute myocardial infarction (AMI) patients studied in the recently completed Enhancing Recovery in Coronary Heart Disease (ENRICHD) multicenter clinical trial provides a unique opportunity to examine the importance of self-reported regular physical exercise in a large cohort of patients with a recent AMI who are depressed or report low levels of social support.

We prospectively examined the association between self-reported physical exercise and all-cause mortality and cardiovascular morbidity among 2078 men (N = 1175; 56.5%) and women (N = 903; 43.5%) with an AMI participating in the ENRICHD Trial. Six months after suffering an AMI, patients were surveyed about their exercise habits and were then followed for up to 4 yr.

During an average 2 yr of follow-up, 187 fatal events occurred. Patients reporting regular exercise had less than half the events (5.7%) of those patients reporting they did not regularly exercise (12.0%). After adjustment for medical and demographic variables, the hazard ratio for fatal events was 0.62 (95% CI = 0.44-0.86, P = 0.004). The rate of nonfatal AMI among the exercisers was 6.5% compared with 10.5% who reported no regular exercise. After adjustment for covariates, the hazard ratio for nonfatal AMI was 0.72 (95% CI = 0.52-0.99, P = 0.044).

The present findings demonstrate the potential value of exercise in reducing mortality and nonfatal reinfarction in AMI patients at increased risk for adverse events by virtue of their either being depressed or having low social support.