Prolonged dual antiplatelet therapy after drug-eluting stent implantation improves long-term prognosis for acute coronary syndrome: five-year results from a large cohort study

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.