Abstract
Background: Despite the use of advanced treatment techniques, coronary artery disease (CAD) still remains the main cause of left ventricular (LV) dysfunction and heart failure. Participation in cardiac rehabilitation (CR) programs can lead to a number of beneficial effects, but some patients do not demonstrate the expected improvement. The aim of this study is to evaluate the impact of CR on changes in exercise capacity with regard to the presence of LV dysfunction. Methods: A group of 428 patients with CAD were consecutively admitted to an outpatient comprehensive cardiac rehabilitation program comprising 24 exercise sessions of interval training on cycle ergometers, three times a week for 45 min, and a health education. The patients were compared in two subgroups, i.e., with LV systolic dysfunction (LVEF < 50%, n = 175) and LVEF ≥ 50% (n = 253). Results: In the LVEF < 50% group, the exercise capacity improved by 1 ± 0.78 MET (median 1.15 MET), and 0.86 ± 0.77 MET (median 1.08 MET) in the LVEF ≥ 50% group. Women with LVEF < 50% demonstrated a significant increase in exercise capacity by 1.2 MET, while those with LVEF ≥ 50% did not display any such increase. All men, regardless of LVEF, exhibited a similar improvement in exercise capacity greater than 1 MET. Conclusions: An outpatient eight-week cardiac rehabilitation program based on 45 min aerobic interval training sessions three times a week appears less effective for women with CAD and EF ≥ 50%. In this group, the proposed training intervention is insufficient in improving exercise capacity to an extent that could indicate a reduction in mortality risk.