Evaluation of the Use of Dual Antiplatelet Therapy beyond the First Year after Acute Coronary Syndrome

Abstract

Clinical practice guidelines recommend extending dual antiplatelet therapy (DAPT) beyond 1 year after acute coronary syndrome (ACS) in patients with high ischemic risk and without high bleeding risk. The aim of this study was to identify variables associated with DAPT prolongation in a cohort of 1967 consecutive patients discharged after ACS without thrombotic or hemorrhagic events during the following year. The sample was stratified according to whether DAPT was extended beyond 1 year, and the factors associated with this strategy were analyzed. In 32.2% of the patients, DAPT was extended beyond 1 year. Overall, 770 patients (39.1%) were considered candidates for extended treatment based on PEGASUS criteria and absence of high bleeding risk, and DAPT was extended in 34.4% of them. The presence of a PEGASUS criterion was associated with extended DAPT in the univariate analysis, but not history of bleeding or a high bleeding risk. In the multivariate analysis, a history of percutaneous coronary intervention (odds ratio (OR) = 1.8, 95% confidence interval (CI) 1.4-2.4), stent thrombosis (OR = 3.8, 95% CI 1.7-8.9), coronary artery disease complexity (OR = 1.3, 95% CI 1.1-1.5), reinfarction (OR = 4.1, 95% CI 1.6-10.4), and clopidogrel use (OR = 1.3, 95% CI 1.1-1.6) were significantly associated with extended use. DAPT was extended in 32.2% of patients who survived ACS without thrombotic or hemorrhagic events. This percentage was 34.4% when the candidates were analyzed according to clinical guidelines. Neither the PEGASUS criteria nor the bleeding risk was independently associated with this strategy.