Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Jul 30, 2025
Date Accepted: Mar 17, 2026
Personalized Smartphone Messaging for Secondary Prevention After Percutaneous Coronary Intervention: Randomized Controlled Trial
ABSTRACT
Background:
Cardiac rehabilitation (CR) improves outcomes after percutaneous coronary intervention (PCI), but participation remains suboptimal due to barriers such as distance, cost, and lack of referral. Mobile health (mHealth) interventions may enhance secondary prevention by improving accessibility and engagement.
Objective:
This study aimed to evaluate the clinical effectiveness and user acceptability of a patient-specific smartphone messaging application (AnSim) in improving cardiovascular (CV) risk factors among patients who recently underwent PCI.
Methods:
This was a single-blinded, 2-arm randomized controlled trial conducted at 2 hospitals in Korea. A total of 120 patients who underwent PCI within the prior month was randomly assigned (1:1) to receive either a smartphone-based message intervention via the AnSim app plus usual care (intervention group) or usual care alone (control group). The intervention comprised personalized educational and motivational messages tailored by behavioral stage and risk profile, delivered 6 times per week for 6 months. The primary outcome was change in blood pressure at 6 and 9 months. Secondary outcomes were changes in lipid profiles, HbA1c, BMI, smoking status, physical activity, and achievement of guideline-recommended risk factor targets. User acceptability was assessed via questionnaire.
Results:
There were no significant differences between groups in blood pressure or secondary endpoints at 6 or 9 months. However, within the intervention group, patients who read more messages (>median) showed greater health diary engagement and were more likely to meet ≥4 recommended CV risk factor targets at 9 months (69.0% vs. 19.2%, P <0.001). Patients with improved blood pressure at 9 months had read significantly more messages (110.3 vs 83.3 days, P = .02). Overall user satisfaction with the app was high, with 87% finding messages helpful and 81% expressing a desire to continue receiving them.
Conclusions:
Although no significant between-group differences were found in primary outcomes, patients with higher message engagement demonstrated improved cardiovascular risk profiles and greater adherence to guideline-recommended targets. This suggests that individualized, theory-based mHealth interventions may be beneficial for motivated users and warrant further long-term study. Clinical Trial: Clinical Research Information Service (CRIS) KCT0002361; https://cris.nih.go.kr/cris
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.