title: Low response to clopidogrel is associated with cardiovascular outcome after coronary stent implantation.
abstract: OBJECTIVE
  To assess whether low response to clopidogrel influences cardiovascular outcome after coronary stent implantation in a consecutively measured cohort of patients with coronary stent implantation.
  
  
  RESULTS
  A total of 379 consecutive patients with symptomatic coronary artery disease (CAD), (stable angina n = 206 and acute coronary syndrome, n = 173) treated with percutaneous coronary stenting were enrolled in this trial. Responsiveness to clopidogrel was assessed by ADP (20 micromol/L)-induced aggregometry at least 6 h (mean 34.8+/-25.9 h) after administration of a loading dose of 600 mg clopidogrel. Platelet inhibition < 30% was defined as low response to clopidogrel. At 3-month follow-up, the primary outcome of a combined major cardiovascular event including non-fatal myocardial infarction, non-fatal ischaemic stroke, or cardiovascular death was evaluated. Twenty-two patients (5.8%) were classified as low responders. Compared with patients who adequately responded to clopidogrel, a low responder had a significantly higher risk of major cardiovascular events [22.7 vs. 5.6%; odds ratio, 4.9; 95% confidence interval (CI), 1.66-14.96; P = 0.004]. After adjustment for other factors influencing cardiovascular outcome, low response to clopidogrel and severe left ventricular dysfunction were independently associated with a major cardiovascular event within 3 months (hazard ratio for low response to clopidogrel, 3.71; 95% CI, 1.08-12.69; P = 0.037).
  
  
  CONCLUSIONS
  Low response to clopidogrel in patients with symptomatic CAD treated by stenting significantly enhances the occurrence of cardiovascular events and death. The evaluation of low response to clopidogrel may help to identify patients at increased risk who may benefit from intensified antiplatelet strategy.
authors.affiliation: Medizinische Klinik III, Universitätsklinikum Tübingen, Eberhard Karls-Universität Tübingen, Otfried-Müller-Str. 10, D-72076 Tübingen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Geisler
authors.forename: Harald
authors.initials: H
authors.lastname: Langer
authors.forename: Magdalena
authors.initials: M
authors.lastname: Wydymus
authors.forename: Katrin
authors.initials: K
authors.lastname: Göhring
authors.forename: Christine
authors.initials: C
authors.lastname: Zürn
authors.forename: Boris
authors.initials: B
authors.lastname: Bigalke
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Stellos
authors.forename: Andreas E
authors.initials: AE
authors.lastname: May
authors.forename: Meinrad
authors.initials: M
authors.lastname: Gawaz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077144:Clopidogrel; D003324:Coronary Artery Disease / Q000401:mortality / Q000628:therapy*; D018572:Disease-Free Survival; D004351:Drug Resistance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D012044:Regression Analysis; D015607:Stents; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017211:Treatment Failure
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine