Level 2: Mid-level evidence
Joint guidelines (from the American Heart Association, American College of Cardiology, and others) recommend dual-antiplatelet therapy (clopidogrel plus aspirin) for at least one year following placement of a drug-eluting stent (Circulation. 2007;115:813-818). A pair of recent open-label trials, analyzed together, evaluated the effects of switching to aspirin alone after one year. A total of 2,701 patients who were free of major cardiac events and bleeding for ≥12 months following percutaneous coronary intervention with a drug-eluting stent were randomized to continued dual-antiplatelet therapy vs. aspirin alone. In a median follow-up of 19.2 months, there were no significant differences in the primary outcome, a composite of MI and cardiovascular death (1.5% vs. 0.9%). There were also no significant differences in the rates of all-cause mortality (1.5% vs. 1%), MI (0.7% vs. 0.5%), stroke (0.7% vs. 0.3%), stent thrombosis (0.4% vs. 0.3%), or revascularization (2.7% vs. 1.9%). Dual therapy was associated with a borderline increase in the composite of MI, stroke, or all-cause mortality (2.6% vs. 1.5% P=0.051, NNH 90) (N Engl J Med. 2010;362:1374-1382).