Participation in Cardiac Rehabilitation and Survival After Coronary Artery Bypass Graft Surgery

Abstract

Background— Cardiac rehabilitation (CR) is recommended for all patients after coronary artery bypass surgery, yet little is known about the long-term mortality effects of CR in this population. Methods and Results— We performed a community-based analysis on residents of Olmsted County, Minnesota, who underwent coronary artery bypass surgery between 1996 and 2007. We assessed the association between subsequent outpatient CR attendance and long-term survival. Propensity analysis was performed. Cox proportional hazards regression was then used to assess the association between CR attendance and all-cause mortality adjusted for the propensity to attend CR. We identified 846 eligible patients (age 66±11 years, 76% men, and 96% non-Hispanic whites) who survived at least 6 months after surgery, of whom 582 (69%) attended CR. During a mean (±SD) follow-up of 9.0±3.7 years, the 10-year all-cause Kaplan-Meier mortality rate was 28% (193 deaths). Adjusted for the propensity to attend CR, participation in CR was associated with a 10-year relative risk reduction in all-cause mortality of 46% (hazard ratio, 0.54; 95% confidence interval, 0.40–0.74; P <0.001) and a 10-year absolute risk reduction of 12.7% (number needed to treat=8). There was no evidence of a differential effect of CR on mortality with respect to age (≥65 versus <65 years), sex, diabetes, or prior myocardial infarction. Conclusions— CR attendance is associated with a significant reduction in 10-year all-cause mortality after coronary artery bypass surgery. Our results strongly support national standards that recommend CR for this patient group.