Long-term mortality and MACE outcomes of yoga-based cardiac rehabilitation in patients with CABG: a 15-year legacy study of a randomized controlled trial

This study reports the 15th year follow-up of a previously reported monocentric, randomized controlled trial comparing the effectiveness of yoga vs. conventional exercise-based cardiac rehabilitation (CR) on mortality and major adverse cardiovascular outcomes in middle-aged, male patients who underwent coronary artery bypass graft surgery (CABG). Three hundred male patients, aged 53.32 (SD, 6.72) years, were recruited for CABG at Narayana Institute of Cardiac Sciences, India, in 2005, followed by random assignment into a yoga-based cardiac rehabilitation program (YCRP) or conventional exercise-based cardiac rehabilitation program (CCRP). This legacy study reports the extended follow-up outcomes for all-cause mortality and cardiovascular events for a median of 14·14 years (IQR 13.82-14.47) since randomisation in 2005. The YCRP group received lectures on yoga philosophy combined with sequential phase-wise administration of yoga modules suited for their pre-and post-operative health status with gradual phase-wise addition of physical postures to initially administered relaxation-based techniques, under continued home-based practice model monitored telephonically until 12 months post-surgery related discharge from the hospital. The CCRP group received conventional exercise-based cardiac rehabilitation with similar phase-wise administration. Both study groups were under continued outpatient department-based care with 6 monthly review sessions until 2020. The exploratory follow-up outcomes [the all-cause mortality, and the major adverse cardiac events (MACE)] were analyzed using an intention-to-treat approach comparing the initially randomized study groups. MACE was a composite of cardiovascular death, nonfatal myocardial infarction, or stroke. The study staff determined the occurrence of death from the medical records or telephonic calls and ascertained it by matching and identifying information reported by participants/or their family members. The Cox proportional hazard estimates and Kaplan-Meier Curve with Log-rank test estimates were used to compare the mortality and MACE outcomes between the study groups. Participants of the YCRP group exhibited significantly reduced risk of all-cause mortality [HR = 0.41 (95% CI = 0.16-0.91, P = 0.02)] and trends of reduction in MACE outcomes [HR = 0.57 (95% CI = 0·30-1.04, P = 0.065)] compared to the CCRP. No significant interaction effects were observed between the intervention and the baseline covariates, such as age, ejection fraction values, or presence of comorbidities. This first-ever long-term follow-up established the survival advantage of the YCRP over CCRP for patients who underwent coronary artery bypass graft surgery (CABG). The results support the utility of yoga-based CR as an alternative to CCRP in low-resource settings.