i-CARE: A Smartphone-Based Intervention to Enhance Cardiac Rehabilitation in Coronary Artery Disease – A randomized controlled trial

The global shortage of healthcare professionals creates challenges in managing chronic diseases. This study evaluated a remotely delivered, theory-based self-care support intervention, "Internet-based CArdiac Rehabilitation Enhancement (i-CARE)", delivered through a smartphone application to enhance self-management in patients with coronary artery disease (CAD). In this assessor-blinded, two-arm randomized controlled trial conducted at two regional hospitals in Hong Kong, community-dwelling adults with angiographically confirmed CAD were randomly assigned (1:1) to standard care or the i-CARE intervention. i-CARE included personalized risk assessment, skill-building, and app-based support to improve self-care behaviors. The primary outcome was change in CAD self-care behaviors, secondary outcomes were self-reported health status, health-related quality of life (HRQoL), physiological and biomarkers. Of 294 participants randomized (n=147 per group), the i-CARE group showed significant greater improvements in self-care maintenance (ꞵ=4.055, 95%CI 1.420-6.691, p=0.003) and self-care confidence (ꞵ=5.609, 95%CI 1.089-10.129, p=0.015) at 3 months, sustained at 6 months. For secondary outcomes, the intervention also resulted in significant reductions in systolic (ꞵ=-3.725, 95%CI -7.322- -0.128, p=0.042) and diastolic (ꞵ= -2.153, 95%CI -4.228--0.079, p=0.042) blood pressure and improvements in HRQoL at 3 months (ꞵ=0.208, 95%CI 0.073-0.343, p=0.003), with persistent benefits for diastolic blood pressure and HRQoL sustained at 6 months. No significant differences were observed for cardiac-specific health status, blood glucose, lipid profile, or waist-to-height ratio. Remotely delivered i-CARE intervention effectively promote self-care among CAD patients and may help address critical healthcare workforce shortages, while also conferring secondary benefits in blood pressure and HRQoL.