Prior chronic clopidogrel therapy is associated with increased adverse events and early stent thrombosis

Despite the growing use of clopidogrel, limited data exist regarding the prognostic significance of chronic clopidogrel therapy in patients sustaining acute coronary syndrome (ACS). Our aim was to determine whether patients sustaining ACS while on chronic clopidogrel therapy have a worse prognosis than clopidogrel-naive patients. A total of 5,386 consecutive ACS patients were prospectively characterised and followed-up for 30 days. Of them, 680 (13 %) were treated with clopidogrel prior to the index ACS. Major adverse cardiovascular events (MACE) were defined as death, recurrent ACS, stroke and/or stent thrombosis. Compared with clopidogrel-naive, chronic clopidogrel-treated patients were older (66 ± 12 vs 63 ± 13, respectively; p