Short-term and Long-term Feasibility, Safety, and Efficacy of High-Intensity Interval Training in Cardiac Rehabilitation: The FITR Heart Study Randomized Clinical Trial
Short-term and Long-term Feasibility, Safety, and Efficacy of High-Intensity Interval Training in Cardiac Rehabilitation: The FITR Heart Study Randomized Clinical Trial
As compared to moderate-intensity continuous training (MICT), high-intensity interval training (HIIT) has reported improving the amount of oxygen consumption (VO2) in patients with coronary artery disease (CAD). Current international cardiac rehabilitation (CR) directed toward further investigation for the effect of HIIT. Hence, Taylor and colleagues (2020) conducted a study titled “Short-term and Long-term Feasibility, Safety, and Efficacy of High-Intensity Interval Training in Cardiac Rehabilitation: The FITR Heart Study Randomized Clinical Trial” published in JAMA cardiology. Summary of findings is given below:
Objective:
To compare HIIT with MICT, for safety, efficacy, adherence, and feasibility of improving VO2 peak in CAD patients.
Method:
In this single-centre, randomized clinical test, 96 participants between age 18 – 80 years, angiographically proven CAD was enrolled. Out of those 96, 93 patients were cleared medically to participate in the study following physical exercise test. The gathering of knowledge occurred between May 2016 – December 2018.
The intervention included a 40-minute MICT program (usual care) or a 4 × 4-minute HIIT program. Participants were indulged in completing 3 sessions per week i.e., 2 supervised and 1 home-based session for 4 weeks and following that 3 home-based sessions per week for 48 weeks.
Change in VO2 peak from baseline to 4 weeks was the first study outcome. This was measured by a physical exertion test. Testing also occurred at 3, 6, and 12 months. Safety, cardiovascular risk factors, feasibility, adherence, and quality of life were secondary outcome
Findings:
Investigators found improved cardiorespiratory fitness with the HIIT program after 4-week supervision. However, after 12 months MICT and HIIT had similar improved outcomes and therefore the superior effect of HIIT wasn’t maintained for the future. The study reports that HIIT has greater efficacy with the mean difference (MD) of VO2 peak between HIIT and MICT being 1.7ml/kg/min. This is often clinically important because the development in VO2 peak of 1 ml/kg/min during the CR program is been linked to a 6% decrease in hospital admission and a 13% decrease in mortality because of all-cause. Both MICT and HIIT has been shown to cut back systolic and diastolic pressure in a patient with hypertension at baseline. Investigators also add that better outcome of HIIT may only continue inpatient who maintains 3 sessions of HIIT per week following supervised CR.
Limitations:
Authors acknowledge a few study limitations like participants belonged to one single centre and also the number of female participants was low. The treating physician was chargeable for the optimization of drug therapy because the primary intervention was conducted within the CR setting. Prescription of exercise intensity was supported by the rating of perceived exertion (RPE). This increased protocol applicability and resulted in a very wide selection of coaching intensities. The study lacks evidence that patients aiming at the RPE range will inherently increase their workload over some time. Some patients did not follow the prescribed exercise program where some patients within the MICT group exercised at higher intensities and more frequently than what was prescribed.
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