Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: Digital technologies have the potential to address many of the challenges associated with the traditional center-based CR (CBCR), but the remote home-based cardiac rehabilitation(HBCR) model remains a challenge. Objective: This study is designed to investigate the feasibility, and efficacy of a smartwatch-facilitated HBCR model in patients with coronary heart disease (CHD). Methods: It was a single-center, randomized, non-blind, and parallel-controlled study. We recruited patients aged 18 years or older with coronary heart disease from a tertiary hospital in Jilin Province, China. The intervention group received a 3-month smartwatch-based HBCR program involving remotely delivered real-time feedback, supervision, and education. The control group received conventional HBCR. Adherence is the primary outcome of the trial, assessed by the Home-Based Cardiac Rehabilitation Exercise Adherence Scale. The secondary outcomes include cardiopulmonary function, measured by cardiopulmonary exercise testing, anxiety (General Anxiety Disorder-7), depression(Patient Health Questionnaire-9), and quality of life (36-Item Short Form Health Survey) at 3 months. Results: Between January 1, 2023, and December 30, 2023, 62 patients (mean age 59.93±10.06 years), of whom 33.3% were female and 66.% were male, were recruited and subsequently randomly assigned to the smartwatch group (n=32) or control group (n=30). No difference was detected in the baseline characteristics between the two groups. After the intervention, the subjects in the smartwatch group performed significantly better in peak VO2, home-based cardiac rehabilitation adherence, GAD-7, PHQ-9, and some other parameters than those in the control group. Conclusions: This feasibility study showed that the smartwatch device was well-accepted and effective in supporting a home-based cardiac rehabilitation model for patients with coronary heart disease (CHD). Clinical Trial: Clinical Trials Registry: ChiCTR2400088039; https://www.chictr.org.cn/bin/project/edit?pid=215602