HIIT improves exercise capacity in cardiovascular rehabilitation for CAD, HF, and atrial fibrillation

Disclaimer: This pre-print has undergone review by the Working Group; however, it has not received formal endorsement from the Guideline Executive Committee or the Canadian Association of Cardiovascular Prevention and Rehabilitation (CACPR) Board. As such, the content does not reflect their official positions, does not represent official guidance, and may be subject to change. Exercise training is a cornerstone of Cardiovascular Rehabilitation (CR) and, as of now, moderate-to-vigorous continuous exercise training (MICT) is the standard. New exercise modalities in the context of CR are constantly being explored to improve patient outcomes. These Canadian Association of Cardiovascular Prevention and Rehabilitation (CACPR) exercise training recommendations provide a synthesis of evidence-informed recommendations from existing documents, including recommendations around High-Intensity Interval training (HIIT). CACPR created a pan-Canadian Exercise Working Group with various knowledge users (e.g., kinesiologists/exercise physiologists, physiotherapists, cardiologists, and patients) with expertise in CR-based exercise, who developed knowledge gap questions related to exercise training based on a literature review and synthesis of all available recommendations. An independent evidence-synthesis team performed a rapid review and meta-analyses to address the questions. The working group used this data to develop relevant recommendations. The final guidelines include 12 recommendations for CR exercise, including nine from previous documents and three new recommendations based on HIIT. The previous recommendations address exercise assessments and prescriptions for CR for various patient profiles. The new recommendations suggest that HIIT can be used to improve exercise capacity in patients with coronary artery disease (CAD), heart failure (HF) or atrial fibrillation. They also state that HIIT is superior to MICT in patients with CAD, that patients with HF should be considered for either HIIT or MICT and that any HIIT interval duration can be used as part of CR. Overall, these recommendations provide guidance for exercise in Canadian CR programs.