Effectiveness of Aerobic Exercise-Based Phase II Cardiac Rehabilitation on Functional Capacity and Quality of Life After CABG; A Randomized Controlled Trial

Abstract

Background: Cardiac rehabilitation usually incorporates exercises as central to recovery after coronary artery bypass grafting (CABG). However, locally generated evidence from outpatient physiotherapy based Phase-II cardiac rehabilitation services in Pakistan remains limited.
Objective: To determine whether a structured aerobic exercise cardiac rehabilitation program improves functional capacity and quality of life compared to usual cardiac rehabilitation in clinically stable post-CABG patients.
Methodology: This study was a two arm randomized controlled trial enrolling 30 participants aged 40-75 years with left ventricular ejection fraction of 35%-44%. Participants were randomized to aerobic exercise training group (n=15) or usual care group (n=15). The intervention was delivered three times per week and comprised of warm-up, progressive aerobic training at 40%-60% of heart rate reserve as well as Borg rating of perceived exertion 11-14 and cool-down with symptom and haemodynamic monitoring. Outcomes were assessed at baseline and end of week 10. Primary analysis used ANCOVA for post intervention adjusted for baseline 6 Minute Walk Test (6MWT) for functional capacity and SF-36 for quality of life.
Results: Baseline 6MWT distance was similar between groups. At the end of week 10, the adjusted between-group difference favored aerobic training by 61.14 m (95% CI 51.60-70.68; p<0.001; partial η²=0.865). SF-36 domain scores also favored aerobic training across all domains, and all domain level comparisons survived Holm-Bonferroni correction with partial η² range 0.339–0.592.
Conclusions: These preliminary findings suggest that a moderate intensity, physiotherapist supervised aerobic exercise program may improve functional capacity and quality of life after CABG.