Aerobic Reconditioning After Cardiac Surgery Using a Predictive Exercise Model

Aerobic exercise is essential in early cardiac rehabilitation after cardiac surgery. While cardiopulmonary exercise testing (CPET) is the reference standard, it is often impractical in the early postoperative phase. This single-center randomized controlled trial evaluated a six-minute walk test (6MWT)-derived predictive equation for exercise prescription versus a traditional symptoms-based approach (Borg CR10 scale). Patients aged 30-65 years, admitted to inpatient rehabilitation one week after cardiac surgery (CABG, valve, or combined), were randomized 1:1 to 14 supervised cycling sessions over two weeks. Outcomes included feasibility, safety, workload progression, functional capacity (6MWT), physical performance (SPPB), and quality of life (EQ-5D). Of 118 enrolled patients, 109 completed the program. No serious exercise-related adverse events occurred. The 6MWT-based group started at higher workloads and achieved greater cumulative training volume. Both groups improved in functional capacity, physical performance, and quality of life, demonstrating non-inferiority of the 6MWT method. The 6MWT-derived predictive equation provides a safe, feasible, and effective alternative for aerobic exercise prescription when CPET is unavailable.