Clinical question: Is there a clinical benefit to continuing dual antiplatelet therapy for more than 12 months after drug-eluting stent placement?

Background: Current guidelines recommend dual antiplatelet therapy for at least 12 months after the placement of a drug-eluting stent. However, no randomized trials have addressed the effects of dual therapy beyond 12 months.

Study design: Randomized, open-label trial.

Setting: Twenty-two cardiac centers in South Korea.

Synopsis: Investigators looked at 2,701 patients, all of whom had undergone drug-eluting stent placement followed by dual therapy with aspirin and clopidogrel for at least 12 months with no major cardiac, cerebrovascular, or bleeding events during that time. Patients were randomized to continue aspirin plus clopidogrel or aspirin alone. The median therapy was 19 months.

Dual therapy led to no significant difference in the primary outcome of myocardial infarction or death from cardiac causes compared with aspirin alone (1.8% vs. 1.2%), nor in any secondary outcomes.

This study has several limitations, including an open-label design. An unexpectedly low event rate dilutes the power of the study to detect clinically important treatment effects.

Bottom line: This study showed no benefit to continuing clopidogrel for more than 12 months after drug-eluting stent placement in addition to aspirin; however, it was significantly underpowered.

Citation: Park SJ, Park DW, Kim YH, et al. Duration of dual antiplatelet therapy after implantation of drug-eluting stents. N Engl J Med. 2010;362(15):1374-1382.

Reviewed for TH eWire by Robert Chang, MD, Anita Hart, MD, Hae-won Kim, MD, Robert Paretti, MD, Helena Pasieka, MD, and Matt Smitherman, MD, University of Michigan, Ann Arbor.

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