Association between outpatient cardiac rehabilitation and all-cause mortality after cardiovascular surgery: A propensity score-matched analysis

Objectives: Cardiac rehabilitation (CR) is a class I recommendation in the treatment guidelines for cardiovascular disease; however, its postoperative prognostic effects after surgery are not fully understood. Therefore, this study aimed to examine the effect of multidisciplinary outpatient CR on postdischarge all-cause mortality in patients who underwent cardiovascular surgery. Methods: This retrospective cohort study included consecutive patients who underwent elective cardiovascular surgery between April 2015 and March 2021. Patients were categorized into CR and non-CR groups. The primary outcome measure was all-cause mortality. Propensity score-matching analysis was performed to minimize selection bias and differences in clinical characteristics. The propensity score for each patient was produced using logistic regression analysis, with the CR group and the subsequent 27 variables as the dependent and independent variables, respectively. Results: In our cohort (n = 1095), 51 patients (4.7%) died during the follow-up period (mean, 1042 days). The CR group had a significantly lower mortality rate than the non-CR group (hazard ratio, 0.45; 95% CI, 0.21-0.95; P = .036). After propensity score matching adjusted for confounders, the association between CR and reduced risk of all-cause mortality remained (hazard ratio, 0.35; 95% CI, 0.14-0.85; P = .02). Conclusions: Postdischarge multidisciplinary outpatient CR in patients who underwent cardiovascular surgery was associated with a substantial survival benefit, which persisted after adjusting for variables, including age, operative factors, physical and cognitive functions, and nutritional status.