High-Intensity Interval Training Programs Versus Moderate-Intensity Continuous Training for Individuals With Heart Failure: A Systematic Review and Meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 38862032 · doi:10.1016/j.apmr.2024.05.028
What was done
Authors systematically searched electronic databases through January 23, 2023, for randomized controlled trials (RCTs) comparing high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in patients with heart failure (HF). Two reviewers independently screened studies, extracted data using CONSORT and TIDieR guidelines, and assessed study quality using the Tool for the Assessment of Study Quality in Exercise (TESTEX) scale. The primary outcome was peak oxygen consumption (Vo2 peak).
What was found
Fifteen RCTs (553 total patients with HF) with moderate to good overall methodological quality were included. HIIT improved Vo2 peak significantly more than MICT overall (MD: 1.49 mL/kg/min; I² = 66%; P < .001; n = 541, 15 RCTs). In heart failure with reduced ejection fraction (HFrEF), the largest benefit over MICT occurred with long-interval (≥4 min) and high-volume (≥15 min total) HIIT (MD: 2.11 mL/kg/min; P < .001; n = 261, 6 RCTs), while short-interval (≤1 min) high-volume HIIT (MD: 0.91 mL/kg/min; P = .12; n = 71, 3 RCTs) and short-interval low-volume HIIT (MD: 0.54 mL/kg/min; P = .05; n = 68, 3 RCTs) showed smaller or non-significant effects. In patients with HF with perceived ejection fraction, HIIT was not significantly superior to MICT (MD: 0.55 mL/kg/min; P = .32; n = 141, 3 RCTs).
Why it matters
This review shows that protocol structure influences the efficacy of HIIT in heart failure, with long-interval, high-volume protocols providing superior cardiorespiratory fitness gains over standard moderate-intensity continuous exercise in patients with reduced ejection fraction.
Limits
Subgroup analyses were based on small sample sizes (68 to 261 participants across 3 to 6 RCTs per protocol category), limiting precision. Moderate-to-high statistical heterogeneity was present in the primary analysis (I² = 66%), and the abstract reported no data on clinical outcomes such as mortality, hospitalizations, or adverse events.
Cited by
- supports High-intensity interval training (HIIT) is an effective intervention for improving health outcomes in patients with heart failure and atrial fibrillation.