Physical Activity and Mortality among Male Survivors of Myocardial Infarction

Abstract

Purpose An inverse association between physical activity (PA) and risk of CHD has been seen in many studies, but evidence for benefits of PA after myocardial infarction (MI) in reducing mortality is limited. Methods Using data from the Health Professionals Follow-up Study cohort, we followed male survivors of MI. Short- and long-term changes in PA from before to after MI were calculated, and participants without ambulation impairment were classified into maintained low, decreased, increased, or maintained high PA categories. Cox models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for mortality across PA and PA change categories. Results During a mean of 14 yr of follow-up of 1651 incident nonfatal MI cases, we documented 678 deaths, 307 were due to cardiovascular disease. The adjusted HR for all-cause mortality comparing ≥21 with ≤1.5 MET·wk⁻¹ of PA before MI was 0.73 (95% CI = 0.59–0.89, P_trend = 0.03). Compared with men who maintained low PA before and after MI, men who maintained high PA had a 39% (95% CI = 25–50) lower risk of all-cause mortality, and those who had a long-term increase in PA from before to after MI had a 27% (95% CI = 6–43) lower risk. Walking for ≥30 min·d⁻¹ after MI was associated with a 29% lower mortality (HR = 0.71, 95% CI = 0.58–0.84), independent of walking pace, and walking pace after MI was inversely associated with mortality (HR = 0.67, 95% CI = 0.49–0.92). Conclusions Maintaining a high PA or having a long-term increase in PA from before to after MI was associated with lower mortality among male MI survivors. Walking time and walking pace after MI were each inversely associated with mortality.