Cardiac rehabilitation is associated with improved long-term outcomes after coronary artery bypass grafting

Background — Although cardiac rehabilitation (CR) has proven to have short- and mid-term benefit in treatment of coronary artery disease, its long-term benefit in patients who have undergone coronary artery bypass grafting (CABG) is less certain. Our objective was to examine the late outcomes of patients who attended CR within the first year after CABG.

Methods — Adult CABG patients referred to Toronto Rehabilitation Institute (CR group: were referred and attended at least 1 session; No-CR group: were referred but did not attend) between January 1996 and September 2008 were identified through linkages with clinical and provincial administrative databases for comorbidities and outcome ascertainment. The primary outcome was a composite of all-cause mortality, acute myocardial infarction, stroke or repeat revascularization (major adverse cardiac and cerebrovascular events [MACCE]). The secondary outcome was all-cause mortality. Multivariable Cox proportional hazard models were used to assess the CR treatment effect, adjusting for baseline characteristics.

Results — The study cohort consisted of 5,000 patients—3,685 (73.7%) in the CR group and 1,315 (26.3%) in the No-CR group. Median referral time was 32.5 days, and follow-up was 13.1 years. The CR group patients, compared with the No-CR group, were younger (age 62.6 ± 9.6 vs 64.0 ± 10.5 years), were more likely to be male (85.0% vs 79.5%), and had fewer cardiac comorbidities. In adjusted analyses, the CR group was associated with decreased MACCE (hazard ratio 0.83, 95% confidence interval 0.75-0.91, P < 0.0001) and a higher adjusted survival at 15 years (66.3% vs 60.1%, hazard ratio 0.76, 95% confidence interval 0.68-0.84, P < 0.0001), as compared with the No-CR group.

Conclusions — There was a reduction in MACCE and late mortality associated with CR attendance, highlighting the importance of patient referral and participation in CR after CABG.