Impact of Adherence to Guideline‐Directed Prevention Strategies on Clinical Outcomes in Patients With Coronary Artery Disease and Diabetes Mellitus Following Acute Coronary Syndrome: A 3‐Year Cohort Study

ABSTRACT Background Coronary artery disease (CAD) and diabetes mellitus (DM) significantly increase the risk after acute coronary syndrome. This study evaluated adherence to guideline‐directed secondary prevention strategies and demonstrated their substantial impact on reducing rehospitalization and mortality in this population. Methods A retrospective cohort study was conducted on 987 CAD and DM patients admitted for ACS between 2015 and 2018. Adherence to seven evidence‐based secondary prevention strategies was assessed: smoking cessation, physical activity, antiplatelet therapy, statins, blood pressure control, ACEi/ARB therapy, and SGLT‐2i therapy. Patients were categorized into groups based on the number of recommendations followed (0–2, 3–4, and 5+). Primary outcomes included rehospitalization and all‐cause mortality over a 3‐year follow‐up period. Results At baseline, only 12.4% of patients adhered to five or more recommendations, which dramatically increased to 71.9% by the 3‐year follow‐up. Individual adherence to each of blood pressure control (HR = 0.81, 95% CI: 0.70–0.94), ACEi/ARB therapy (HR = 0.77, 95% CI: 0.67–0.89), and SGLT‐2i therapy (HR = 0.79, 95% CI: 0.68–0.92) significantly reduced rehospitalization risk. Similarly, adherence to these therapies individually reduced mortality risk (HR = 0.78, 95% CI: 0.67–0.91; HR = 0.74, 95% CI: 0.63–0.87; and HR = 0.72, 95% CI: 0.61–0.85, respectively). Importantly, a stepwise increase in adherence was associated with a dose‐dependent reduction in mortality (HR = 0.65, 95% CI: 0.52–0.81, p < 0.05). Conclusion This study highlights the critical role of comprehensive, multifactorial secondary prevention in its association with improved long‐term outcomes in patients with CAD and DM following ACS.