Efficacy and safety of antiplatelet-combination therapy after drug-eluting stent implantation

Background/Aims: Combination single-pill therapy can improve cost-effectiveness in a typical medical therapy. However, there is a little evidence about the efficacy and tolerability of combination single-pill antiplatelet therapy after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Methods: From June to November 2012, in total, 142 patients who met the following criteria were enrolled: at least 18 years old; successful PCI with DES at least 3months earlier; and regular medication of aspirin and clopidogrel with no side effects. After Verify Now P2Y12 and aspirin assays, the combination single pill of aspirin and clopidogrel was given and laboratory tests were repeated 6 weeks later. Results: At baseline, the incidence of aspirin resistance, defined as aspirin reaction unit (ARU) ≥ 550, was 9.2%, that of clopidogrel resistance, defined as P2Y12reaction unit (PRU) ≥ 230, was 46.5%, and that of percent inhibition of PRU