Abstract
BACKGROUND: To investigate the most appropriate dual antiplatelet therapy (DAPT) duration for patients with acute coronary syndrome (ACS) after drug-eluting stent (DES) implantation in the largest cardiovascular center of China. METHODS: We enrolled 5,187 consecutive patients with ACS who received DES from January to December 2013. Patients were divided into four groups based on DAPT duration: standard DAPT group (11-13 months, n=1,568) and prolonged DAPT groups (13-18 months [n=308], 18-24 months [n=2,125], and >24 months [n=1,186]). Baseline characteristics and 5-year clinical outcomes were recorded. RESULTS: Baseline characteristics were similar across the four groups. Among the four groups, those with prolonged DAPT (18-24 months) had the lowest incidence of major adverse cardiovascular and cerebrovascular events (MACCEs) (14.1% vs. 11.7% vs. 9.6% vs. 24.2%, P<0.001), all-cause death (4.8% vs. 3.9% vs. 2.1% vs. 2.6%, P<0.001), cardiac death (3.1% vs. 2.6% vs. 1.4% vs. 1.9%, P=0.004), and myocardial infarction (MI) (3.8% vs. 4.2% vs. 2.5% vs. 5.8%, P<0.001). The incidence of bleeding was not different among the four groups (9.9% vs. 9.4% vs. 11.0% vs. 9.4%, P=0.449). Cox multivariable analysis showed that prolonged DAPT (18-24 months) was an independent protective factor for MACCEs (hazard ratio [HR] 0.802, 95% confidence interval [CI] 0.729-0.882, P<0.001), all-cause death (HR 0.660, 95% CI 0.547-0.795, P<0.001), cardiac death (HR 0.663, 95% CI 0.526-0.835, P<0.001), MI (HR 0.796, 95% CI 0.662-0.957, P=0.015), and target vessel revascularization (HR 0.867, 95% CI 0.755-0.996, P=0.044). Subgroup analysis for high bleeding risk showed that prolonged DAPT remained an independent protective factor for all-cause death and MACCEs. CONCLUSION: For patients with ACS after DES, appropriately prolonging the DAPT duration may be associated with a reduced risk of adverse ischemic events without increasing the bleeding risk.