Patient-centred medical tools for sustained motivation in cardiac rehabilitation of patients with heart failure: a multicentre randomized controlled trial

Background Despite strong guideline recommendations, participation in and long-term adherence to exercise therapy for heart failure (HF) remain suboptimal. This multicentre randomized trial evaluated whether a mobile application-based exercise support programme integrated with wearable devices improved exercise tolerance and muscle strength vs standard exercise prescription. Methods This investigator-initiated randomized-controlled trial was conducted across three tertiary care hospitals in Japan. Outpatients with HF were randomized 1:1 to an application-based programme or standard exercise prescriptions. The application delivered personalised aerobic and resistance training through real-time step and pulse rate monitoring, algorithm-guided goal setting, educational content, and clinician feedback. The primary outcome was the change in peak (Δpeak) oxygen uptake (VO2) at 12 weeks. Secondary outcomes included Δpeak VO2 at 24 weeks, and exploratory outcomes included changes in skeletal muscle strength. Analyses were conducted in the full analysis set, with the per-protocol set defined as ≥30 days of app use within 12 weeks. Between-group differences in Δpeak VO2 were estimated using analysis of covariance adjusted for allocation factors and baseline peak VO2. Results Between October 2023 and October 2024, 100 patients were randomised (49 intervention, 51 control); median age was 63 years (IQR 56–71), 26% were female, and all had New York Heart Association class I–II symptoms. The between-group differences in Δpeak VO2 at 12 and 24 weeks were 0.23 mL/kg/min (95% confidence interval [CI] −0.56 to 1.02, p=0.561) and 0.72 mL/kg/min (95% CI −0.15 to 1.59, p=0.103), respectively. The corresponding differences in the per-protocol set were 0.28 mL/kg/min (95% CI −0.55 to 1.11, p=0.509) and 0.93 mL/kg/min (95% CI 0.02 to 1.84, p=0.045). Hand-grip and knee-extension strength improved significantly and progressively in the intervention group. No serious intervention-related adverse events occurred. Conclusion The mobile application-based exercise support programme did not improve peak VO2 at 12 weeks; however, sustained engagement with it produced a modest but potentially meaningful gain at 24 weeks, alongside gains in muscle strength.