Background: Exercise-based cardiac rehabilitation increases peak oxygen uptake (peak VO₂), which is an important predictor of mortality in cardiac patients. However, it remains unclear which exercise characteristics are most effective for improving peak VO₂ in coronary artery disease (CAD) patients. Proof of concept papers comparing Aerobic Interval Training (AIT) and Moderate Continuous Training (MCT) were conducted in small sample sizes and findings were inconsistent and heterogeneous. Therefore, we aimed to compare the effects of AIT and Aerobic Continuous Training (ACT) on peak VO₂, peripheral endothelial function, cardiovascular risk factors, quality of life and safety, in a large multicentre study.
Methods: Two-hundred CAD patients (LVEF >40%, 90% men, mean age 58.4 ± 9.1 years) were randomized to a supervised 12-week cardiac rehabilitation programme of three weekly sessions of either AIT (90-95% of peak heart rate (HR)) or ACT (70-75% of peak HR) on a bicycle. Primary outcome was peak VO₂; secondary outcomes were peripheral endothelial function, cardiovascular risk factors, quality of life and safety.
Results: Peak VO₂ (ml/kg/min) increased significantly in both groups (AIT 22.7 ± 17.6% versus ACT 20.3 ± 15.3%; p-time<0.001). In addition, flow-mediated dilation (AIT+34.1% (range -69.8 to 646%) versus ACT+7.14% (range -66.7 to 503%); p-time<0.001) quality of life and some other cardiovascular risk factors including resting diastolic blood pressure and HDL-C improved significantly after training. Improvements were equal for both training interventions.
Conclusions: Contrary to earlier smaller trials, we observed similar improvements in exercise capacity and peripheral endothelial function following AIT and ACT in a large population of CAD patients.
Keywords: Cardiac rehabilitation; Coronary artery disease; Endothelial function; Exercise intensity; Secondary prevention; Training modality.
Copyright © 2014. Published by Elsevier Ireland Ltd.