Background: The optimal duration of dual antiplatelet therapy remains controversial.
Methods and results: Between December 2006 and March 2008, 823 patients were enrolled in a prospective multicenter registry for 3-month dual antiplatelet therapy (aspirin 100-200mg+clopidogrel 75 mg daily) followed by aspirin mono-therapy after zotarolimus-eluting stents (ZES). Major exclusion criteria were: cardiogenic shock, stent thrombosis (ST)-segment elevation myocardial infarction (MI) within 48h, previous drug-eluting stent implantation, severe left ventricular dysfunction, bifurcation lesions requiring 2-stenting, left main and graft lesions. The primary outcome was a composite of cardiac death, MI, or ST at 1 year. The median duration of dual antiplatelet therapy was 95 days (interquartile range 90-101). At 1 year, 3 patients (0.4%) had cardiac deaths, 3 patients (0.4%) had MI, and 4 patients (0.5%) had definite or probable ST, leading to the primary outcome in 5 patients (0.6%). Death, MI, or any revascularization occurred in 68 patients (8.3%). Among patients who were event-free at 3 months (n=812), clopidogrel was discontinued at 3 months in 661 patients and was continued for longer than 3 months in 151 patients. Discontinuation of clopidogrel at 3 months did not increase the primary outcome (HR 0.90; 95%CI, 0.09-9.02), death, MI, or any revascularization (HR 0.89; 95%CI, 0.48-1.67) after adjustment for the propensity score.
Conclusions: Three-month dual antiplatelet therapy seems to be feasible after ZES implantation in relatively low-risk patients.
Trial registration: ClinicalTrials.gov NCT00794014.