Ambrosio G， Steinhubl S， Gresele P， Tritto I， Zuchi C， Bertrand ME， Lincoff AM， Moses JW， Ohman EM， White HD， Mehran R， Stone GW.
    aDivisions of Cardiology bInternal Medicine， University of Perugia School of Medicine， Perugia， Italy cThe Medicines Company， Zurich Switzerland dHopital Cardiologique， Lille， France eThe Cleveland Clinic， Cleveland， Ohio fColumbia University Medical Center and the Cardiovascular Research Foundation， New York gDuke University Medical Center， Durham， North Carolina， USA hAuckland City Hospital， Auckland， New Zealand.
Abstract
    AIMS: Presentation with an acute coronary syndrome (ACS) on chronic aspirin therapy is an independent predictor of adverse short-term outcomes. Whether this finding applies to chronic thienopyridine use， and with the contemporary invasive management of ACS， is unknown.
    METHODS AND RESULTS: In ACUITY， 13 819 patients with moderate and high-risk ACS were studied; patients transferred from an outside hospital were excluded from the present analysis， given uncertain preadmission antiplatelet status. Endpoints included major adverse cardiovascular events (MACE: death， myocardial infarction， or unplanned revascularization)， major bleeding， and net adverse clinical events (NACE). Among 11 313 study patients， 31% were naive for antiplatelet agent， 49% were receiving aspirin alone， and 20% were on dual antiplatelet therapy. Chronic antiplatelet users were older and had a higher risk profile. After adjusting for baseline differences， chronic antiplatelet therapy (single or dual) was not associated with an increased incidence of 30-day MACE， bleeding， or NACE. However， patients on chronic aspirin or dual antiplatelet therapy at presentation had significantly higher 1-year rates of MACE [odds ratio (95% confidence interval)=1.17 (1.01-1.36)， P=0.03 and 1.29 (1.02-1.64)， P=0.03， respectively]. Patients presenting on dual antiplatelet therapy had significantly greater adjusted MACE at 1-year than those on aspirin alone [odds ratio (95% confidence interval)=1.34 (1.15-1.56)， P<0.0001].
    CONCLUSION: Contrary to earlier studies， prior antiplatelet therapy was not associated with an increased risk of adverse outcomes at 30 days in invasively managed patients. Such use did， however， independently predict 1-year ischemic MACE， with outcomes worse for patients presenting on chronic dual antiplatelet therapy compared with aspirin alone.