Evidence base for pharmacotherapy effectiveness in patients with acute myocardial infarction: The role of treatment adherence assessment using EMIAS data

Background In real-world clinical practice, the effectiveness of medications for secondary prevention of acute myocardial infarction (AMI) is limited by low patient adherence. The lack of systematic adherence analysis inevitably distorts the evidence base for the effectiveness of these medications. Objective To investigate 1-year adherence to post-AMI therapies (statins, dual antiplatelet therapy (DAPT), and neurohormonal antagonists) using the Proportion of Days Covered (PDC) metric and evaluate its impact on treatment effectiveness through data from the Electronic Medical Information and Analytical System (EMIAS). Method The study included 276 patients who had undergone AMI. The follow-up period was 12 months after discharge from the hospital. Adherence was considered acceptable at PDC ≥80%. Efficacy was assessed based on endpoints for DAPT, low-density lipoprotein cholesterol (LDL-C) reduction>50% for statin therapy and left ventricular ejection fraction (LVEF) for heart failure (HF) therapy. Results Annual adherence rates were critically low: 38.8% for DAPT, 37.6% for statin therapy, and 24.2% for neurohormonal therapy of HF. High adherence versus non-adherence was associated with a significant reduction in the risk of composite cardiovascular events for DAPT (p = 0.047); for statins, a reduction in LDL-C ≥50% was achieved significantly more often (31.6% vs 13.2%); and for HF patients, a significantly greater increase in LVEF was observed (55.6% vs 50.12%). Conclusion The evidence base for the effectiveness of long-term pharmacotherapy in real-world clinical practice should be derived from the analysis of variables of interest exclusively within the treatment-adherent patient cohort.