Duration of dual antiplatelet therapy after implantation of drug-eluting stents

Objective:To evaluate the potential benefit of prolonging 12-month dual antiplatelet therapy among patients with coronary artery disease receiving zotarolimus-eluting stents.Methods:From Sep.2006 to Jue.2009,patients with coronary artery disease undergoing PCI with zotarolimus-eluting stents in the cardiology department of Beijing Anzhen Hospital were enrolled.Our clinical endpoint focused on major adverse cardiac or cerebrovascular events(MACCE),death,nonfatal myocardial infarction(MI),stroke,and repeat revascularization.Follow up was carried out by telephone or outpatient interview.To overcome the defect of non-randomized comparisons,multivariable Cox proportional-hazards regression was carried out to adjust for potential confounding factors.Results:The average follow-up was(28.4±7.4) months.A toal of 915 appropriate patients were divided to two groups: 12-month DAPT group(362) and 12-month DAPT group(553).Rates of MACCE(3.6% VS.4.3%,P=0.87) and TVR(2.2% VS.2.5%,P=0.97) did not differ between 12-month DAPT group and 12-month DAPT group.After adjusted by the multivariable Cox proportional-hazards regression,still no significant differences of the endpoints mentioned above were observed between the two groups.Rates of death MI or stroke were not significantly different between the two groups either.Conclusion:The use of dual antiplatelet therapy for a period longer than 12 months in patients who had received zotarolimus-eluting stents was not significantly more effective than aspirin monotherapy in reducing adverse cardiac or cerebrovascular event.