Cardiac Rehabilitation Improves Long-term Survival of Diabetic Patients after Coronary Artery Bypass Graft Surgery: A Multi-center Study with 13-y Follow-up

Background and aims: Cardiac rehabilitation (CR) is recommended for patients following coronary artery bypass graft (CABG) surgery. However, findings on the effect of CR on long term survival are mixed; these are based primarily on randomized control trials (RCTs) involving selected samples and rarely patients with diabetes mellitus (DM). We investigated the impact of participation in routinely provided CR after CABG surgery on 13-year survival (median 10.7 years) overall and by DM status.

Materials and methods: A multicenter prospective cohort study including 1,153 patients from seven medical centres who had undergone CABG surgery during 2004-2007, 1000 of whom (87%) were alive at 12-month after surgery and had information on CR participation after CABG surgery. All-cause mortality was ascertained through the Israeli Ministry of Internal Affairs Register (through March 2018) and DM status through patient`s report or use of glucose lowering medications or diagnosis of DM in the medical record. Cox regression models were used to study the impact of CR participation on survival clustering on hospital and adjusting for propensity score to account for the non-randomized allocation to CR. Analyses were stratified by DM status.

Results: 419 (42%) patients had DM. Participation in CR reached 28% in the total cohort as well as according to DM status. Overall, CR participation following CABG surgery was associated with lower mortality [hazard ratio (HR) 0.46, 95% CI 0.34-0.61, p<0.0001], even after adjustment for propensity score, [adjusted hazard ratio (AHR) 0.65, 95% CI 0.47-0.90, p=0.01], regardless of DM status.

Conclusion: Participation in routinely provided CR was associated with improved long-term survival after CABG surgery. The survival benefit is evident only several years after the intervention and is significant in both DM-free and DM-positive patients. The finding stress the importance of promoting participation in cardiac rehabilitation programs in all cardiac patient groups.