Efficacy of Early Short-term Training on Thrombogenesis in Patients Following Coronary Bypass Surgery

Although the benefit of cardiac rehabilitation following coronary artery bypass graft (CABG) is well-established, it is underused. The current investigation will adopt an early, intensive, short-term and supervised aerobic training at moderate-intensity. The inclusion criteria are diagnosed coronary artery disease (CAD) and clinical indication for elective first-time CABG. Regular physical exercise is associated with overall reduced risk of primary cardiac arrest. Previous study demonstrated that moderate-intensity exercise training reduced resting and strenuous exercise-induced activation of platelet and possibly coagulation. Our main research question is that whether the short-term CR program in the present investigation will ameliorate hemostatic imbalance at rest and platelet coagulation activation at maximal stress exercise. This is designed to be a prospective randomized controlled study. Sixty men who are scheduled to receive elective CABG in Chang Gung Memorial Hospital at Linkuo will be enrolled in the study. They will be randomized into two groups: intensive training (IT) and usual rehabilitation (UR). Participants in the IT group will receive intensive aerobic training at moderate intensity after CABG. A submaximal exercise test will be performed for intensity prescription. They will receive two training sessions per day and at least 20 sessions in total. The CR group will receive usual CR program. After intervention, each participant will receive a maximal exercise test. Additionally, six-minute walk test, generic and disease-specific quality of life, will be collected before and after training. Additional 20 age-matched non-sedentary and healthy men without training will be recruited as control group. Venous blood will be sampled three times (before and after rehabilitation and maximal stress test) for the assessment of platelet activation by flow cytometer and activity of coagulation factors. Mean platelet volume, and platelet activation markers (platelet-bound CD62P%G, CD63%G, CD40L%G) will be analyzed. Various coagulation and fibrinolysis factors will be quantified. We hypothesized that this training program will ameliorate the prothrombotic state and attenuate platelet reactivity and coagulation induced by strenuous exercise in patients after CABG. Hopefully, this clinical investigation will establish an early short-term rehabilitation model following CABG and its efficacy for clinical use.