title: Effectiveness and safety of drug-eluting stents in Ontario.
abstract: BACKGROUND
  The placement of drug-eluting stents decreases the frequency of repeat revascularization procedures in patients undergoing percutaneous coronary intervention (PCI) in randomized clinical trials. However, there is uncertainty about the effectiveness of drug-eluting stents, and increasing concern about their safety, in routine clinical practice.
  
  
  METHODS
  From the Cardiac Care Network of Ontario's population-based clinical registry of all patients undergoing PCI in Ontario, Canada, we identified a well-balanced cohort of 3751 pairs of patients, matched on the basis of propensity score, who received either bare-metal stents alone or drug-eluting stents alone during an index PCI procedure between December 1, 2003, and March 31, 2005. The primary outcomes of the study were the rates of target-vessel revascularization, myocardial infarction, and death.
  
  
  RESULTS
  The 2-year rate of target-vessel revascularization was significantly lower among patients who received drug-eluting stents than among those who received bare-metal stents (7.4% vs. 10.7%, P<0.001). Drug-eluting stents were associated with significant reductions in the rate of target-vessel revascularization among patients with two or three risk factors for restenosis (i.e., presence of diabetes, small vessels [<3 mm in diameter], and long lesions [> or =20 mm]) but not among lower-risk patients. The 3-year mortality rate was significantly higher in the bare-metal-stent group than in the drug-eluting-stent group (7.8% vs. 5.5%, P<0.001), whereas the 2-year rate of myocardial infarction was similar in the two groups (5.2% and 5.7%, respectively; P=0.95).
  
  
  CONCLUSIONS
  Drug-eluting stents are effective in reducing the need for target-vessel revascularization in patients at highest risk for restenosis, without a significantly increased rate of death or myocardial infarction.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada. tu@ices.on.ca
authors.forename: Jack V
authors.initials: JV
authors.lastname: Tu
authors.forename: James
authors.initials: J
authors.lastname: Bowen
authors.forename: Maria
authors.initials: M
authors.lastname: Chiu
authors.forename: Dennis T
authors.initials: DT
authors.lastname: Ko
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
authors.forename: Yaohua
authors.initials: Y
authors.lastname: He
authors.forename: Robert
authors.initials: R
authors.lastname: Hopkins
authors.forename: Jean-Eric
authors.initials: JE
authors.lastname: Tarride
authors.forename: Gord
authors.initials: G
authors.lastname: Blackhouse
authors.forename: Charles
authors.initials: C
authors.lastname: Lazzam
authors.forename: Eric A
authors.initials: EA
authors.lastname: Cohen
authors.forename: Ron
authors.initials: R
authors.lastname: Goeree
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D023903:Coronary Restenosis / Q000453:epidemiology / Q000517:prevention & control*; D018572:Disease-Free Survival; D016503:Drug Delivery Systems; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology; D017202:Myocardial Ischemia / Q000401:mortality / Q000628:therapy*; D009864:Ontario; D011474:Prosthesis Design; D012042:Registries; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects