摘要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 diff erent 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.