High-intensity Interval Training Dosage for Heart Failure and Coronary Artery Disease Cardiac Rehabilitation. A Systematic Review and Meta-analysis

Introduction and objectives: High-interval intensity training (HIT) has been suggested to improve peak VO2 in cardiac rehabilitation programs. However, the optimal HIT protocol is unknown. The objective of this study was to identify the most effective doses of HIT to optimize peak VO2 in coronary artery disease (CAD) and heart failure (HF) patients. Methods: A search was conducted in 6 databases (MEDLINE, Web of Science, LILACS, CINAHL, Academic Search Complete, and SportDiscus). Studies using a HIT protocol in CAD or HF patients and measuring peak VO2 were included. The PEDro Scale and Cochrane Collaboration tools were used. Results: Analyses reported significant improvements in peak VO2 after HIT in both diseases (P =.000001), with a higher increase in HF patients (P =.03). Nevertheless, in HF patients, there were no improvements when the intensity recovery was ≤ 40% of peak VO2 (P =.19) and the frequency of training was ≤ 2 d/wk (P =.07). There were significant differences regarding duration in CAD patients, with greater improvements in peak VO2 when the duration was \textless 12 weeks (P =.05). In HF, programs lasting \textless 12 weeks did not significantly improve peak VO2 (P =.1). Conclusions: The HIT is an effective method for improving peak VO2 in HF and CAD, with a significantly greater increase in HF patients. The recovery intervals should be active and be between 40% and 60% of peak VO2 in HF patients. Training frequency should be ≥ 2 d/wk for CAD patients and ≥ 3 d/wk for HF patients. Full English text available from: www.revespcardiol.org/en