title: Characterizing the spectrum of in-stent restenosis: implications for contemporary treatment.
abstract: BACKGROUND
  Reports addressing treatment of in-stent restenosis (ISR) are principally derived from clinical trials.
  
  
  OBJECTIVE
  To characterize the spectrum of ISR in an unselected population, and to explore clinical and angiographic factors determining management.
  
  
  METHODS
  During a prespecified six-month period before the introduction of drug-eluting stents, consecutive cases of ISR that were identified during clinically driven cardiac catheterization at five hospitals offering all approved treatment modalities for ISR were prospectively registered.
  
  
  RESULTS
  ISR was identified in 363 patients; 301 (84%) had one ISR lesion and 62 (16%) had multiple lesions. Unstable clinical presentations accounted for 51%, including 15% with ST-elevation myocardial infarction. The median interval (25th, 75th percentiles) from stent insertion to angiographic diagnosis of ISR was eight months (Q1,Q3: 4,15), with a median stented length of 18 mm (Q1,Q3: 15,28). The majority of lesions (60%) displayed a diffuse ISR pattern (Mehran types 2 and 3). ISR type was independent of time to re-presentation, diabetes, arterial territory and total stent length. Treatment included percutaneous coronary intervention (PCI) alone (n=139 [38%]), PCI with brachytherapy (n=105 [29%]), medical therapy (n=60 [17%]) and coronary artery bypass graft surgery (n=59 [16%]). Medical therapy was associated with small vessel size and recurrent ISR, and coronary artery bypass graft surgery was associated with multiple lesions, as well as diffuse, occlusive and recurrent ISR. For patients treated percutaneously, PCI treatment alone was more common for focal restenosis and after ST-elevation myocardial infarction, and brachytherapy was the more common treatment for diffuse and recurrent ISR, and stable angina.
  
  
  CONCLUSIONS
  These data provide a benchmark description of the spectrum of ISR with which the impact of drug-eluting stents may be compared and better understood.
authors.affiliation: Division of Cardiology, University of British Columbia, Vancouver.
authors.forename: Gordon E
authors.initials: GE
authors.lastname: Pate
authors.forename: May
authors.initials: M
authors.lastname: Lee
authors.forename: Karin
authors.initials: K
authors.lastname: Humphries
authors.forename: Eric
authors.initials: E
authors.lastname: Cohen
authors.forename: Robert
authors.initials: R
authors.lastname: Lowe
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Fox
authors.forename: Robert
authors.initials: R
authors.lastname: Teskey
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Buller
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data*; D001918:Brachytherapy / Q000706:statistics & numerical data*; D002170:Canada / Q000453:epidemiology; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy*; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy; D011446:Prospective Studies; D012042:Registries; D015607:Stents / Q000009:adverse effects*