title: Prolonged Clopidogrel Use is Associated with Improved Clinical Outcomes Following Drug-Eluting But Not Bare Metal Stent Implantation.
abstract: BACKGROUND
  Guidelines recommend clopidogrel use for 6-12 months following drug-eluting stent (DES) implantation and 1-12 months following bare metal stent (BMS) implantation. The role of clopidogrel beyond 12 months is unclear.
  
  
  METHODS
  We linked hospital administrative, community pharmacy and cardiac revascularization data to determine clopidogrel use and outcomes for all patients (those with acute presentations and those with stable angina) receiving a coronary stent in British Columbia 2004-2006, with follow-up until the end of 2008. Cox proportional hazard regression was performed to evaluate the effect of clopidogrel duration (≤12 vs. >12 months) on outcomes following BMS or DES implantation. Patients who died ≤12 months from index stent placement were excluded.
  
  
  RESULTS
  A total of 15,629 patients were included in the study. Of 3599 patients who received at least one DES and 12,030 patients who received only BMS, 1326 (37 %) and 2121 (18 %), respectively, filled a prescription for clopidogrel >12 months from the index procedure. The mean duration of clopidogrel was 406 ± 35 days and 407 ± 37 days in the prolonged use (>12 months) DES and BMS cohorts, respectively, compared with 224 ± 112 days (p < 0.001) and 122 ± 117 days (p < 0.001), respectively, for patients receiving clopidogrel ≤12 months. Clopidogrel use beyond 12 months was associated with a reduction in mortality [hazard ratio (HR) 0.66, 95 % confidence interval (CI) 0.45-0.97] and the composite of mortality and readmission for myocardial infarction (HR 0.72, 95 % CI 0.55-0.94) in patients treated with DES, but not BMS alone. Prolonged clopidogrel use was not associated with bleeding-related mortality.
  
  
  CONCLUSIONS
  Clopidogrel use beyond 12 months was associated with a reduction in death and hospitalization for myocardial infarction following DES, but not BMS, implantation. Our findings support a longer duration of clopidogrel therapy for patients treated with DES.
authors.affiliation: Department of Cardiology, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK. nick.cruden@ed.ac.uk.|University of Edinburgh, Edinburgh, UK. nick.cruden@ed.ac.uk.
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Cruden
authors.affiliation: Royal Bournemouth Hospital, Bournemouth, UK.
authors.forename: Jehangir N
authors.initials: JN
authors.lastname: Din
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Janssen
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: W Peter
authors.initials: WP
authors.lastname: Klinke
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: Reginald
authors.initials: R
authors.lastname: Smith
authors.affiliation: Providence Health Care, Vancouver, Canada.
authors.forename: Ron G
authors.initials: RG
authors.lastname: Carere
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: J David
authors.initials: JD
authors.lastname: Hilton
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: Anthony Della
authors.initials: AD
authors.lastname: Siega
authors.affiliation: Victoria Heart Institute Foundation, Victoria, Canada.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Robinson
mesh_terms: D000077144:Clopidogrel; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals / Q000627:therapeutic use*; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D012189:Retrospective Studies; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D008670:Metals; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine