Antiplatelet therapy and drug-eluting stents

Is 3 months of dual antiplatelet therapy enough after a drug-eluting stent? Researchers attempted to find out in a trial of more than 3100 patients with stable coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI) with a zotarolimus-eluting stent. Patients were then prescribed aspirin (100-200 mg daily) with clopidogrel (Plavix, 75 mg daily) for 3 months or 12 months with roughly the same number of patients in each group. The primary endpoint was net adverse clinical and cerebral events, including all-cause death, myocardial infarction, stroke, or major bleeding, with the secondary endpoint of major cardiac events. The primary outcome rate was the same in each group (P = 0.002 for noninferiority). Cardiac event rate was 8.3% in the short-term group and 7.4% in the long-term group (hazard ratio, 1.12; 95% confidence interval, 0.87-1.45). More importantly between 91 and 360 days (after stopping clopidogrel in the short-term group), the primary outcome was identical between the two groups at 2.6%. The authors conclude that in patients with stable CAD who were treated with zotarolimus-eluting stents, 3 months of dual antiplatelet therapy was noninferior to 12 months with regard to major clinical events and without a significantly higher risk of stent thrombosis (JAMA 2013;310:2510-2522). Larger studies are needed to definitively change the duration of therapy; however, this study offers some comfort for those PCI patients who need to stop clopidogrel early due to bleeding or surgery.