Background:Studies have suggested that use of prolonged dual antiplatelet therapy (DAPT) following new generation drug-eluting stent implantation may increase costs and potential bleeding events.This study aimed to investigate the association of DAPT status with clinical safety in patients undergoing everolimus-eluting stent (EES) implantation in the SEEDS study (A Registry to Evaluate Safety and Effectiveness of Everolimus Drug-eluting Stent for Coronary Revascularization) at 2-year follow-up.Methods:The SEEDS study is a prospective,multicenter study,where patients (n =1900) with small vessel,long lesion,or multi-vessel diseases underwent EES implantation.Detailed DAPT status was collected at baseline,6-month,1-and 2-year.DAPT interruption was defined as any interruption of aspirin and/or clopidogrel more than 14 days.The net adverse clinical events (NACE,a composite endpoint of all-cause death,all myocardial infarction (MI),stroke,definite/probable stent thrombosis (ST),and major bleeding (Bleeding Academic Research Consortium Ⅱ-Ⅴ)) were investigated according to the DAPT status at 2-year follow-up.Results:DAPT was used in 97.8％ of patients at 6 months,69.5％ at 12 months and 35.4％ at 2 years.It was observed that the incidence of NACE was low (8.1％) at 2 years follow-up,especially its components of all-cause death (0.9％),stroke (1.1％),and definite/probable ST (0.7％).DAPT was not an independent predictor of composite endpoint of all-cause death/MI/stroke (hazard ratio [HR]:0.693,95％confidence interval [CI]:0.096-4.980,P =0.715) and NACE (HR:1.041,95％ CI:0.145-7.454,P =0.968).Of 73 patients who had DAPT interruption,no patient had ST at 12-month,and only 1 patient experienced ST between 1-and 2-year (1.4％).There was a high frequency of major bleeding events (53/65,82.5％) occurred in patients receiving DAPT treatment.Conclusions:Prolonged DAPT use was not associated with improved clinical safety.The study emphasized that duration of DAPT needs to be shortened in Chinese patients following EES implantation (ClinicalTrials.gov identifier:NCT 01 157455).