Long-Term Use of Antiplatelet Therapy in Real-World Patients with Acute Myocardial Infarction: Insights from the PIPER Study

The aim of this study was to assess long-term drug adherence and prognosis in real-world patients discharged on dual-antiplatelet therapy (DAPT) after acute myocardial infarction (AMI). A retrospective cohort analysis using administrative databases kept by eight local health units was performed. DAPT exposure (defined as ≥ 2 prescriptions), adherence, and the occurrence of major adverse events (MACE) were analyzed during a 36-month follow-up. The analysis included 11,101 patients who were discharged alive with a primary diagnosis of AMI. Of these, 5,919 patients (53.31%) were discharged on DAPT without a diagnosis of cancer or anemia, without transient DAPT discontinuation, and represented the study population. DAPT discontinuation occurred in 2,200 patients (37.2%) and in 1,995 (33.7%) after the first 6 and 12 months, respectively, whereas 423 patients (7.1%) were still on DAPT after 36 months. Patients who maintained DAPT up to 12 months had a significantly lower overall mortality, compared with patients who discontinued DAPT after 6 months. Exposure to DAPT at 3 years was associated with reduced all-cause mortality (hazard ratio [HR]: 0.067, 95% confidence interval [CI]: 0.027–0.162, p