Increased Physical Activity Post–Myocardial Infarction Is Related to Reduced Mortality: Results From the SWEDEHEART Registry

BACKGROUND: With increasing survival rates among patients with myocardial infarction (MI), more demands are placed on secondary prevention. While physical activity (PA) efforts to obtain a sufficient PA level are part of secondary preventive recommendations, it is still underutilized. Importantly, the effect of changes in PA after MI is largely unknown. Therefore, we sought to investigate the effect on survival from changes in PA level, post‐MI. METHODS AND RESULTS: Data from Swedish national registries were combined, totaling 22 227 patients with MI. PA level was self‐reported at 6 to 10 weeks post‐MI and 10 to 12 months post‐MI. Patients were classified as constantly inactive, increased activity, reduced activity, and constantly active. Proportional hazard ratios were calculated. During 100 502 person‐years of follow‐up (mean follow‐up time 4.2 years), a total of 1087 deaths were recorded. Controlling for important confounders (including left ventricular function, type of MI, medication, smoking, participation in cardiac rehabilitation program, quality of life, and estimated kidney function), we found lower mortality rates among constantly active (hazard ratio: 0.29, 95% confidence interval: 0.21–0.41), those with increased activity (0.41, 95% confidence interval: 0.31–0.55), and those with reduced activity (hazard ratio: 0.56, 95% confidence interval: 0.45–0.69) during the first year post‐MI, compared with those being constantly inactive. Stratified analyses indicated strong effect of PA level among both sexes, across age, MI type, kidney function, medication, and smoking status. CONCLUSIONS: The present article shows that increasing the PA level, compared with staying inactive the first year post‐MI, was related to reduced mortality.