title: Prognosis of patients suffering an acute coronary syndrome while already under chronic clopidogrel therapy.
abstract: OBJECTIVE
  To assess the prognosis of patients presenting with an acute coronary syndrome (ACS) despite chronic clopidogrel therapy (CCT).
  
  
  BACKGROUND
  CCT has been shown to be beneficial in decreasing the frequency of major adverse cardiovascular events (MACE) in patients after an ACS or drug-eluting stent (DES) implantation. Some patients, however, still suffer thrombotic events while on CCT. The outcome of this particular subgroup of patients is unknown.
  
  
  METHODS
  A cohort of 1,281 patients undergoing percutaneous coronary intervention (PCI) for an ACS was studied. They were divided according to their treatment prior to the ACS. The CCT group was composed of all patients who had been taking clopidogrel for >or=30 days before the onset of the ACS (n = 175) and the no CCT group of all patients not on clopidogrel before the ACS (n = 1,106). Rates of cardiovascular death and myocardial infarction at 6 months' follow-up were compared.
  
  
  RESULTS
  Patients in the CCT group were older (66 +/- 11 vs. 63 +/- 13; P< 0.001), and more often diabetic (46.8 vs. 31.9%; P < 0.01). In-hospital outcomes were similar, including the rate of death and myocardial infarction (no CCT vs. CCT group: 4.2 vs. 2.3%; P = 0.2). At 6 months, patients already taking clopidogrel before the ACS had a higher rate of MACE than patients who were not (18.3 vs. 11.8%; P = 0.02). In multivariate analysis, CCT before the ACS was associated with a hazard ratio of 1.7 for MACE.
  
  
  CONCLUSIONS
  This study suggests that patients suffering an ACS while under on CCT have a poor long-term prognosis, which could be linked to clopidogrel low-response.
authors.affiliation: Department of Internal Medicine, Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bonello
authors.forename: Axel
authors.initials: A
authors.lastname: De Labriolle
authors.forename: Gilles
authors.initials: G
authors.lastname: Lemesle
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Steinberg
authors.forename: Probal
authors.initials: P
authors.lastname: Roy
authors.forename: Rebecca
authors.initials: R
authors.lastname: Torguson
authors.forename: William O
authors.initials: WO
authors.lastname: Suddath
authors.forename: Lowell F
authors.initials: LF
authors.lastname: Satler
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Kent
authors.forename: Augusto D
authors.initials: AD
authors.lastname: Pichard
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
mesh_terms: D054058:Acute Coronary Syndrome / Q000401:mortality / Q000628:therapy*; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000401:mortality; D001241:Aspirin / Q000008:administration & dosage; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality; D000077144:Clopidogrel; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology / Q000401:mortality; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D016016:Proportional Hazards Models; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin