Cardiac Telerehabilitation with a smartwatch and a smartphone gamification application: A feasibility study (Preprint)

BACKGROUND Home-based cardiac rehabilitation (HBCR) utilizing digital health technologies (cardiac telerehabilitation, CTR) has emerged as a practical alternative to conventional center-based cardiac rehabilitation (CBCR), particularly during and after the COVID-19 pandemic. However, maintaining sustained participation in cardiac rehabilitation (CR) remains a challenge. Gamification holds potential to enhance motivation and adherence in CR, but its role in CTR for acute coronary syndrome (ACS) patients remains understudied. OBJECTIVE This feasibility study evaluated the acceptability, safety, and preliminary efficacy of a combination of a gamification-enabled smartphone app and smartwatch supporting CTR after ACS. We focused specifically on participation motivation, adherence to prescribed exercise intensity, and short-term physiological outcomes. METHODS This single-arm, pre-post intervention study was conducted at two Japanese institutions. Sixteen patients diagnosed with ST-elevated myocardial infarction (STEMI) or non-ST-elevated myocardial infarction (NSTEMI) and undergoing percutaneous coronary intervention (PCI) were enrolled after discharge. Each patient received a smartphone and smartwatch connected to the “Shin-po Kei” app, earning points when exercising within their aerobic threshold heart rate ± 10 bpm. The one-month intervention prescribed walking for 30 minutes or more, 3-5 days per week, at Borg scale 11-13 intensity. The primary endpoint was total app usage rate. Secondary endpoints included appropriate exercise rate, changes in peak oxygen consumption (peak VO₂), and changes in perceived exertion using a visual analog scale (VAS). RESULTS The mean patient age was 62 ± 13 years, and 94% were male. The mean intervention duration was 29 ± 6 days, and the overall app usage rate was 59.9%. The appropriate exercise implementation rate was 32.9%. Peak VO₂ significantly increased from 18.4 ± 4.1 to 21.1 ± 5.4 mL/kg/min (P =.004), and the mean VAS score for exercise discomfort decreased from 57 ± 33 to 32 ± 26 (P =.007). A significant positive correlation was observed between total app usage days and days of appropriate exercise performance (r = 0.606, P =.017). No adverse events related to app usage occurred during the study period. CONCLUSIONS This feasibility study suggests that a smartwatch-linked gamified smartphone app may contribute to promoting participation in CTR after ACS, with observed improvements in exercise capacity and reductions in exercise-related discomfort. These findings indicate that gamification could be one component of digital cardiology interventions aimed at improving adherence and supporting recovery in post-ACS CR. Larger randomized controlled trials are needed to confirm efficacy, sustainability, and long-term outcomes. CLINICALTRIAL GamiHeart pilot study (UMIN000046777)