title: Does a well developed collateral circulation predispose to restenosis after percutaneous coronary intervention? An intravascular ultrasound study.
abstract: OBJECTIVE
  To evaluate whether a well developed collateral circulation predisposes to restenosis after percutaneous coronary intervention (PCI).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  58 patients undergoing elective single vessel PCI in a tertiary referral interventional cardiac unit in the UK.
  
  
  METHODS
  Collateral flow index (CFI) was calculated as (Pw-Pv)/(Pa-Pv), where Pa, Pw, and Pv are aortic, coronary wedge, and right atrial pressures during maximum hyperaemia. Collateral supply was considered poor (CFI < 0.25) or good (CFI > or = 0.25).
  
  
  METHODS
  In-stent restenosis six months after PCI, classified as neointimal volume > or = 25% stent volume on intravascular ultrasound (IVUS), or minimum lumen area < or = 50% stent area on IVUS, or minimum lumen diameter < or = 50% reference vessel diameter on quantitative coronary angiography.
  
  
  RESULTS
  Patients with good collaterals had more severe coronary stenoses at baseline (90 (11)% v 75 (16)%, p < 0.001). Restenosis rates were similar in poor and good collateral groups (35% v 43%, p = 0.76 for diameter restenosis, 27% v 45%, p = 0.34 for area restenosis, and 23% v 24%, p = 0.84 for volumetric restenosis). CFI was not correlated with diameter, area, or volumetric restenosis (r2 < 0.1 for each). By multivariate analysis, stent diameter, stent length, > 10% residual stenosis, and smoking history were predictive of restenosis.
  
  
  CONCLUSIONS
  A well developed collateral circulation does not predict an increased risk of restenosis after PCI.
authors.affiliation: Department of Cardiology, Rayne Institute, St Thomas' Hospital Campus, King's College London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Perera
authors.forename: P
authors.initials: P
authors.lastname: Postema
authors.forename: R
authors.initials: R
authors.lastname: Rashid
authors.forename: S
authors.initials: S
authors.lastname: Patel
authors.forename: L
authors.initials: L
authors.lastname: Blows
authors.forename: M
authors.initials: M
authors.lastname: Marber
authors.forename: S
authors.initials: S
authors.lastname: Redwood
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D016022:Case-Control Studies; D003097:Collateral Circulation / Q000502:physiology*; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D015607:Stents; D014463:Ultrasonography