title: The significance of clopidogrel low-responsiveness on stent thrombosis and cardiac death assessed by the verifynow p(2)y(12) assay in patients with acute coronary syndrome within 6 months after drug-eluting stent implantation.
abstract: OBJECTIVE
  Clopidogrel resistance or low-responsiveness may be associated with recurrent atherothrombotic events after drug-eluting stent (DES) implantation. We prospectively evaluated the association between clopidogrel resistance assessed by the Verifynow P(2)Y(12) assay (Accumetrics, San Diego, CA, USA) and stent thrombosis (ST) or cardiac death (CD) in patients with acute coronary syndrome (ACS) within 6 months after DES implantation.
  
  
  METHODS
  We enrolled 237 consecutive patients (160 males, 65.2+/-10.3 years) with ACS who received a DES implantation. The composite endpoint was defined to CD or ST by Academic Research Consortium definitions within 6 months post-implantation. Clopidogrel resistance was defined as <20% inhibition of the P(2)Y(12) receptor.
  
  
  RESULTS
  Baseline demographic characteristics were similar between 142 normal individuals and 95 clopidogrel resistant patients. CD occurred in one case (0.7%) in the normal group and two cases (2.13%) in the resistant group (p=0.344). There was no episode of ST in the normal group and four episodes in the resistant group (4.2%, four definite ST) (p=0.035). Univariate logistic regression revealed an adjusted odds ratio (OR) for composite end point of CD or ST of 9.646 {95% confidence interval (CI) 1.139-81.679}, and multivariate logistic regression for composite end point revealed an OR of 12.074 (95% CI 1.205-120.992).
  
  
  CONCLUSIONS
  Clopidogrel low-responsiveness assessed by the Verifynow P(2)Y(12) assay is an independent predictor of ST and composite end point of ST or CD in patients with ACS within 6 months after DES implantation.
authors.affiliation: Division of Cardiology, Gachon University of Medicine and Science, Gil Medical Center, Incheon, Korea.
authors.forename: Kyounghoon
authors.initials: K
authors.lastname: Lee
authors.forename: Seung-Whan
authors.initials: SW
authors.lastname: Lee
authors.forename: Jun-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Seong-Yoon
authors.initials: SY
authors.lastname: Kim
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Youn
authors.forename: Min-Soo
authors.initials: MS
authors.lastname: Ahn
authors.forename: Jang-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Byung-Su
authors.initials: BS
authors.lastname: Yoo
authors.forename: Junghan
authors.initials: J
authors.lastname: Yoon
authors.forename: Kyung-Hoon
authors.initials: KH
authors.lastname: Choe