Effect of Revascularisation Procedure on Cardiac Rehabilitation Outcome

Background: Coronary artery disease (CAD) representsthe third leading cause of death and disability indeveloped countries. Currently percutaneous coronaryangioplasty (PCA) and coronary artery bypass grafting(CABG) are effective and established treatments for reducingthe symptoms and mortality for coronary disease.Cardiac rehabilitation (CR) has as its overall aim toimprove in function, relieve symptoms and enhance thepatients’ quality of life. The effect of surgery on cardiacrehabilitation has not been investigated using 6-min walktest (6MWT) and heart rate variability (HRV).Methods and results: Thirty-eight patients wereincluded in this study. Patients were divided into twogroups: PCI (n = 22) and CABG (n = 16). A 25 min leadII ECG was recorded for each patient before and after a 6-week CR program. Pre and post 6MWT measures were also obtained to determine the impact of CR on exercise capacity. No significant changes in HRV indices following CR were observed in the PCI group. However,a significant increase/improvement was seen for SDNN(37.9 ± 22.7 vs. 55.6 ± 27.3 ms, p = 0.006), LF (348.4 ± 695.7vs. 1071.8 ± 1241.7 ms2, p = 0.003) and HF (428.3 ± 1034.0 vs.944.7 ± 1713.0 ms2, p = 0.015) in CABG group.Conclusions: Our results suggest that a 6-week CR program increased parasympathetic modulation of cardiac function in subjects who had undergone successful CABG but not in PCI patients. Therefore CR duration and prescribed exercises may need to be re-evaluated and adjusted with respect to the type of revascularisation procedure to maximise the cardiac benefit in patients attending CR.