title: Prior chronic clopidogrel therapy is associated with increased adverse events and early stent thrombosis.
abstract: 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-naïve 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-naïve, chronic clopidogrel-treated patients were older (66 ± 12 vs 63 ± 13, respectively; p<0.01), suffered more from diabetes mellitus, hypertension, dyslipidaemia, prior cardiovascular history, including prior myocardial infarction, revascularisation, coronary artery bypass graft and stroke (p<0.01 for all), and were less likely to present with ST-elevation myocardial infarction (21% vs 45%; respectively; p < 0.001). Prior clopidogrel therapy was associated with a two-fold increase in in-hospital (1.6% vs 0.6%, respectively; p =0.006) as well as 30-day stent thrombosis (2.2% vs 1.0%, respectively; p=0.007). MACE at 30 days was also higher among chronic clopidogrel-treated compared with clopidogrel-naïve patients [12.3% vs 9.4%, respectively; p<0.01]. In multivariate log regression analysis chronic clopidogrel treatment was an independent predictor of stent thrombosis [OR=2.6 (95%CI 1.2-5.6), p=0.001]. Patients sustaining ACS while on chronic clopidogrel treatment are at higher risk for in-hospital and 30-day adverse outcomes, including stent thrombosis.
authors.affiliation: Elad Asher, MD, MHA, Heart Institute, Sheba Medical Center, Tel Hashomer 5265601, Israel, Tel.: +972 3 6352303, Fax: +972 3 534 3888, E-mail: el.asher@gmail.com.
authors.forename: Elad
authors.initials: E
authors.lastname: Asher
authors.forename: Paul
authors.initials: P
authors.lastname: Fefer
authors.forename: Avi
authors.initials: A
authors.lastname: Sabbag
authors.forename: Romana
authors.initials: R
authors.lastname: Herscovici
authors.forename: Ehud
authors.initials: E
authors.lastname: Regev
authors.forename: Israel
authors.initials: I
authors.lastname: Mazin
authors.forename: Nir
authors.initials: N
authors.lastname: Shlomo
authors.forename: Doron
authors.initials: D
authors.lastname: Zahger
authors.forename: Shaul
authors.initials: S
authors.lastname: Atar
authors.forename: Haim
authors.initials: H
authors.lastname: Hammerman
authors.forename: Arthur
authors.initials: A
authors.lastname: Polak
authors.forename: Roy
authors.initials: R
authors.lastname: Beigel
authors.forename: Shlomi
authors.initials: S
authors.lastname: Matetzky
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000628:therapy; D000368:Aged; D002318:Cardiovascular Diseases / Q000150:complications; D000077144:Clopidogrel; D015897:Comorbidity; D001026:Coronary Artery Bypass; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications; D016017:Odds Ratio; D062645:Percutaneous Coronary Intervention; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D011379:Prognosis; D011446:Prospective Studies; D015607:Stents / Q000009:adverse effects*; D020521:Stroke / Q000150:complications; D011795:Surveys and Questionnaires; D013927:Thrombosis / Q000150:complications / Q000209:etiology*; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: ACS; Chronic clopidogrel therapy; stent thrombosis