Abstract
INTRODUCTION: Myocardial Infarction (MI) ranks among the major causes of death and disability globally. The modifiable risk factors are very important not only for its prevention, but also for its long-term management. Adherence to self-care plays a very important part in improving outcomes following MI. However, after MI, patient adherence declines over time. The Theory of Planned Behavior (TPB) is a socio-psychological theory that can be a model to develop focused interventions which will improve self-care practices. METHODS: This quasi-experimental study was conducted on 140 post-MI patients in Fasa City, Iran (2023-2024). They were randomly allocated to the intervention (70) or control (70) group. Participants in the intervention group received a 10-session education program based on the TPB content related to self-care components. The control group only received standard care. Validated scales assessed self-care behavior, TPB constructs (attitude, subjective norms, perceived behavioral control), lifestyle modification and behavioral intention at baseline and 4-month follow-up. RESULTS: There was no significant difference between both groups in terms of demographic and baseline variables and TPB domains (p > 0.05). However, at four months following the intervention, the intervention group showed a significant improvement in all evaluated variables compared to the control group (p < 0.001). CONCLUSION: The TPB-based educational intervention can meaningfully improve the self-care behavior of MI patients. Future work should assess the sustainability over time of these changes, and the feasibility of using digital health technology to support enhanced patient compliance.