Digital Health Technology for Improving Physical Function in Adults With Chronic Heart Failure: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Chronic heart failure (CHF) significantly impairs physical function and quality of life. Although exercise-based cardiac rehabilitation represents a primary therapeutic strategy, participation rates remain low due to logistical barriers. Digital health technologies (DHTs) offer a promising alternative to deliver home-based interventions. However, evidence regarding their specific impact on functional capacity versus daily physical behavior remains inconsistent. Objective: This systematic review and meta-analysis aimed to evaluate the efficacy of DHTs on physical activity and health outcomes in patients with CHF and to identify the intervention characteristics that drive physiological improvement. Methods: We searched Embase, CENTRAL, PubMed, Web of Science, and Joanna Briggs Institute Evidence-Based Practice (JBI EBP) database for randomized controlled trials published between August 2015 and July 2025. Studies comparing DHT interventions with usual care or nondigital active controls in adults with CHF were included. Primary outcomes were functional exercise capacity (6-minute walk distance), cardiorespiratory fitness (peak oxygen uptake), and daily step count. Secondary outcomes included health-related quality of life (Minnesota Living with Heart Failure Questionnaire and Kansas City Cardiomyopathy Questionnaire). Data were synthesized using random-effects models, and the certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Results: In total, 16 unique randomized controlled trials (across 20 publications) involving 3441 participants were included. DHT interventions significantly improved 6-minute walk distance (mean difference [MD] 18.74 m, 95% CI 9.31-28.17; P<.001) and peak oxygen uptake (MD 0.84 mL/kg/minute, 95% CI 0.59-1.09; P<.001) compared with controls. Subgroup analysis revealed that comprehensive hybrid telerehabilitation models drove consistent physiological benefits, whereas standalone app-based interventions demonstrated a uniformly nonsignificant effect (I2=0%). DHTs also significantly reduced symptom-related quality of life burden (Minnesota Living with Heart Failure Questionnaire: MD -5.63, 95% CI -8.55 to -2.71; P<.001), but narrative synthesis revealed highly inconsistent effects on daily step counts, and pooled analysis showed no significant impact on general health status (Kansas City Cardiomyopathy Questionnaire: P=.95). No significant increase in adverse events was reported. Conclusions: DHTs are effective strategies to improve cardiorespiratory fitness and functional capacity in patients with CHF. However, physiological gains do not automatically guarantee increased daily physical activity. The safety and efficacy of these interventions appear to depend on the delivery mode, with structured hybrid models incorporating remote supervision outperforming passive app-based approaches. Future implementation should prioritize personalized, medically supervised closed-loop management systems.