Cardiac Telerehabilitation with a smartwatch and a smartphone gamification app: 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. Clinical Trial: GamiHeart pilot study (UMIN000046777)