Comprehensive cardiac rehabilitation significantly improved strain tolerance in all CAD patients, with HFrEF showing more pronounced improvement than HFmrEF and HFpEF.
Does a three-week cardiac rehabilitation program improve exercise tolerance equally in CAD patients with reduced, mildly reduced, and preserved ejection fraction?
A three-week cardiac rehabilitation program significantly improves exercise capacity in CAD patients across all ejection fraction categories, with the greatest relative improvements observed in those with reduced ejection fraction.
Background. Coronary artery disease (CAD) is the leading cause of heart failure (HF). The beneficial effects of cardiac rehabilitation (CR) in CAD patients are well known but whether they depend on ejection fraction (EF) is rather unknown. Aim. To examine whether CAD pts with reduced, mildly reduced, and preserved EF benefit equally from comprehensive CR in terms of exercise tolerance. Methods. 828 CAD pts attended a three-week CR program at the residential center. Before attending CR all patients underwent an echocardiographic exam after which pts were divided into three groups: heart failure with reduced (HFrEF≤40%), mildly reduced (HFmrEF 41-49%), and preserved EF (HFpEF≥50%). At baseline and at the end of CR exercise stress test (EST) was taken. Results. There were 84 HFrEF pts (10.14%), 246 HFmrEF pts (29.71%), and 498 HFpEF pts (60.15%). At the first EST (EST1) and at the second EST (EST2) HFpEF and HFmrEF patients showed better strain tolerance compared to pts with HFrEF by reaching a higher strain levels and longer duration of EST. However, all three groups showed better strain tolerance at the EST2. Namely, they all reached higher strain level (for all three groups p=0.000) and longer duration of EST (for all three groups p=0.000). Also, in all three groups significantly higher percentage of patients reached submaximal heart rate at the EST2 compared to EST1 (p=0.001 for HFrEF, p=0.006 for HFmrEF, and p=0.000 for HFpEF). Pts with HFrEF had a significantly higher rate of arrhythmia at the EST2 compared to pts with HFmrEF and HFpEF (p=0.009). Improvement of physical strain level and duration of EST on EST2 compared with EST1 was more pronounced in pts with reduced (by 19,2% and 28,7%), than in pts with mildly reduced (by 13,9% and 17,5%) and pts with preserved LVEF (14,1% and 16,8%). Conclusion. Results indicate that CR significantly improved physical strain tolerance in patients with coronary artery diseases independent of ejection fraction. In pts with HFmrEF and HFpEF CR resulted in higher level of strain tolerance than in pts with HFrEF. However, improvement in exercise capacity was more pronounced in pts with HFrEF.
Stojanović et al. (2022) studied this question. Comprehensive cardiac rehabilitation significantly improved strain tolerance in all CAD patients, with HFrEF showing more pronounced improvement than HFmrEF and HFpEF.