Clinical Question

Does prolonged dual antiplatelet therapy after the placement of a drug-eluting stent improve outcomes?

Bottom Line

Prolonging dual antiplatelet therapy with aspirin plus clopidogrel (Plavix) for more than one year after the placement of a drug-eluting stent confers no clinical benefit. (Level of Evidence = 1b)

Synopsis

Current American College of Cardiology guidelines recommend dual antiplatelet therapy following drug-eluting stent placement for at least 12 months (J Am Coll Cardiol. 2011;57(19):1920–1959). Among patients who tolerate dual therapy for 12 months, is there any benefit to prolonged treatment for another two years? In this study, 5,045 patients received a drug-eluting stent and tolerated at least one year of dual antiplatelet therapy with aspirin and clopidogrel. None experienced a stroke, myocardial infarction, revascularization, or major bleeding episode during that period. They were then randomized to receive continued dual therapy or aspirin alone, receiving the drug(s) in an open-label fashion. However, outcomes were adjudicated by a committee that was masked to treatment assignment. The groups were balanced at the start of the study, with a mean age of 62 years; 69% of participants were men and 28% had diabetes mellitus. Approximately 80% were recruited after 12 to 18 months of successful dual antiplatelet therapy (the remainder after a longer period).

Compliance with aspirin was good throughout the trial, although compliance with clopidogrel in the group assigned to dual therapy declined to less than 80% after two years. There was no difference in the likelihood of any individual or combined cardiovascular or bleeding outcomes. Overall, the combination of cardiac death, myocardial infarction, stroke, stent thrombosis, or major bleeding occurred in 3.2% of the aspirin-only group and in 3.8% of the dual therapy group (hazard ratio = 0.84; 95% confidence interval, 0.62 to 1.14).

Study design: Randomized controlled trial (single-blinded)

Funding source: Foundation

Allocation: Concealed

Setting: Outpatient (specialty)

Reference: LeeCWAhnJMParkDKet alOptimal duration of dual antiplatelet therapy after drug-eluting stent implantation: a randomized, controlled trial. Circulation2014; 129( 3): 304– 312.