title: Stent thrombosis, clinical events, and influence of prolonged clopidogrel use after placement of drug-eluting stent data from an observational cohort study of drug-eluting versus bare-metal stents.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the risk of stent thrombosis (ST), clinical outcomes, and the benefits of extended clopidogrel use after drug-eluting stent (DES) implantation.
  
  
  BACKGROUND
  Data are limited regarding uniform evaluation of ST and the influence of clopidogrel continuation beyond 12 months on late events after DES treatment.
  
  
  METHODS
  We identified 7,221 patients who received DES implantation (n = 3,160) or bare-metal stent (BMS) implantation (n = 4,061), and compared long-term adverse outcomes. Additionally, 2,851 patients with DES surviving 12 months without major events were analyzed according to clopidogrel continuation.
  
  
  RESULTS
  The adjusted-risk of overall ST was similar in the 2 groups. After 1 year, however, DES patients showed a higher risk of ST; definite/probable (hazard ratio [HR]: 3.55, 95% confidence interval [CI]: 1.26 to 9.99). The adjusted-risk of death (HR: 0.60, 95% CI: 0.46 to 0.79), death/myocardial infarction (HR: 0.63, 95% CI: 0.49 to 0.81), and target lesion revascularization (HR: 0.32, 95% CI: 0.24 to 0.43) were significantly lower in the DES group than in the BMS group. Continuing clopidogrel beyond 12 months was not associated with a reduced risk for ST (HR: 0.54, 95% CI: 0.07 to 4.23), death (HR: 1.20, 95% CI: 0.55 to 2.66), or death/myocardial infarction (HR: 1.16, 95% CI: 0.56 to 2.42) after DES implantation.
  
  
  CONCLUSIONS
  As compared with BMS, DES showed a similar risk of overall ST, but a higher risk of very late ST. The rates of death, death/myocardial infarction, and target lesion revasuclarization were significantly lower in the DES group. Clopidogrel continuation beyond 1 year did not appear to reduce ST and clinical events after DES implantation.
authors.affiliation: Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Duk-Woo
authors.initials: DW
authors.lastname: Park
authors.forename: Sung-Cheol
authors.initials: SC
authors.lastname: Yun
authors.forename: Seung-Whan
authors.initials: SW
authors.lastname: Lee
authors.forename: Young-Hak
authors.initials: YH
authors.lastname: Kim
authors.forename: Cheol Whan
authors.initials: CW
authors.lastname: Lee
authors.forename: Myeong-Ki
authors.initials: MK
authors.lastname: Hong
authors.forename: Sang-Sig
authors.initials: SS
authors.lastname: Cheong
authors.forename: Jae-Joong
authors.initials: JJ
authors.lastname: Kim
authors.forename: Seong-Wook
authors.initials: SW
authors.lastname: Park
authors.forename: Seung-Jung
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000295:instrumentation* / Q000401:mortality; D000077144:Clopidogrel; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000401:mortality / Q000628:therapy*; D004334:Drug Administration Schedule; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007723:Korea / Q000453:epidemiology; D008297:Male; D008670:Metals; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology / Q000401:mortality; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D018570:Risk Assessment; D015607:Stents; D013927:Thrombosis / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D008670:Metals; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine