Aerobic interval training and continuous training equally improve aerobic exercise capacity in patients with coronary artery disease: The SAINTEX-CAD study

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±9.1years) 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.