title: Levels of circulating CD34+/KDR+ cells do not predict coronary in-stent restenosis.
abstract: BACKGROUND
  Angiographic and clinical parameters are poor predictors of in-stent restenosis. Bone marrow-derived CD34(+) cells that coexpress a receptor for vascular endothelial growth factor (kinase insert domain receptor [KDR]) are committed to endothelial lineage. Mobilization and infusion of CD34(+)/KDR(+) cells accelerates re-endothelialization and reduces neointimal thickness in vascular injury models. Bioengineered stents capturing CD34(+) cells also show expedited re-endothelialization. We examined whether circulating CD34(+)/KDR(+) cell counts can be used to predict restenosis in a bare-metal stent (BMS).
  
  
  METHODS
  CD34(+)/KDR(+) cells were counted by flow cytometry in 124 nondiabetic patients before BMS implantation and the relation to in-stent late luminal loss (LLL) was examined by angiography at 6 months (primary end point). Neointima was also quantified as the maximum percentage area stenosis (M%AS) and percentage volume intima hyperplasia (%VIH) on intravascular ultrasonography (secondary end points).
  
  
  RESULTS
  Multiple linear regression analysis, taking into account implanted stent length and diameter, revealed no relation between CD34(+)/KDR(+) cell counts and LLL (partial regression coefficient b = 0.11; 95% confidence interval [CI], -0.19-0.42; P = 0.46). Similarly, no relation between CD34(+)/KDR(+) cell counts and M%AS or %VIH could be demonstrated. Moreover, the increase in CD34(+)/KDR(+) cell counts over 6 months was unrelated to LLL (b = -0.15; 95% CI, -0.42-0.12; P = 0.28), M%AS, and %VIH.
  
  
  CONCLUSIONS
  Although our study does not exclude a pathophysiologic role for CD34(+)/KDR(+) cells in the formation of neointima, cell counts before percutaneous coronary intervention proved to be unrelated to LLL or intravascular ultrasonographically derived restenosis parameters in coronary BMSs at 6 months.
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium. Electronic address: steven.haine@uza.be.
authors.forename: Steven E
authors.initials: SE
authors.lastname: Haine
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Emeline M
authors.initials: EM
authors.lastname: Van Craenenbroeck
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Vicky Y
authors.initials: VY
authors.lastname: Hoymans
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Hielko P
authors.initials: HP
authors.lastname: Miljoen
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Tom R
authors.initials: TR
authors.lastname: Vandendriessche
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Claeys
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Frederix
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Viviane M
authors.initials: VM
authors.lastname: Conraads
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Johan M
authors.initials: JM
authors.lastname: Bosmans
authors.affiliation: Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium; Department of Cardiology, University of Antwerp, Antwerp, Belgium.
authors.forename: Christiaan J
authors.initials: CJ
authors.lastname: Vrints
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000097:blood* / Q000276:immunology; D002452:Cell Count; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D042783:Endothelial Cells / Q000276:immunology* / Q000473:pathology; D004730:Endothelium, Vascular / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011475:Prosthesis Failure; D015607:Stents; D018084:Ultrasonography, Interventional; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000097:blood*
chemical_list: D018952:Antigens, CD34; D040301:Vascular Endothelial Growth Factor Receptor-2