title: Pivotal, randomized U.S. study of the Symbiottrade mark covered stent system in patients with saphenous vein graft disease: eight-month angiographic and clinical results from the Symbiot III trial.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the clinical and angiographic outcomes of the Symbiot ePTFE covered stent versus bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease.
  
  
  BACKGROUND
  The Symbiot stent was developed to reduce periprocedural complications, by potentially preventing distal embolization, and to serve as a possible barrier to cell migration, thus reducing restenosis.
  
  
  METHODS
  Symbiot III is a prospective, randomized trial of 400 patients at 45 US sites, with 201 patients in the Symbiot group and 199 in the BMS group. Randomization was stratified based on the intended use of embolic protection devices and glycoprotein IIb/IIIa inhibitors. The primary endpoint was percent diameter stenosis (%DS) as measured by quantitative coronary angiography at 8 months. Secondary endpoints included MACE (cardiac death, MI, TVR).
  
  
  RESULTS
  The groups were well matched for all baseline clinical and lesion characteristics. At 8 months, %DS was comparable between groups (30.9% Symbiot, 31.9% BMS, P = 0.80). Although the rates of binary restenosis in the stented segment were similar (29.1% Symbiot, 21.9% BMS, P = 0.17), more patients in the Symbiot group had binary restenosis at the proximal edge (9.0% Symbiot, 1.8% BMS, P = 0.0211). There was no difference in the incidence of MACE between groups (30.6% Symbiot, 26.6% BMS, P = 0.43).
  
  
  CONCLUSIONS
  This study failed to show an advantage for the Symbiot stent in the treatment of degenerated SVGs. This PTFE covered stent does not appear to act as a barrier to prevent restenosis.
authors.affiliation: Center for Cardiac and Vascular Research, Washington Adventist Hospital, Takoma Park, Maryland 20912, USA. mturco@ahm.com
authors.forename: Mark A
authors.initials: MA
authors.lastname: Turco
authors.forename: Maurice
authors.initials: M
authors.lastname: Buchbinder
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Popma
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Weissman
authors.forename: Tift
authors.initials: T
authors.lastname: Mann
authors.forename: Serge
authors.initials: S
authors.lastname: Doucet
authors.forename: Warren L
authors.initials: WL
authors.lastname: Johnson
authors.forename: Joel D
authors.initials: JD
authors.lastname: Greenberg
authors.forename: Katrin
authors.initials: K
authors.lastname: Leadley
authors.forename: Mary E
authors.initials: ME
authors.lastname: Russell
mesh_terms: D000328:Adult; D000368:Aged; D019917:Blood Vessel Prosthesis Implantation; D002170:Canada; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000601:surgery; D023903:Coronary Restenosis / Q000000981:diagnostic imaging*; D023381:Endpoint Determination; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011138:Polytetrafluoroethylene / Q000627:therapeutic use; D011446:Prospective Studies; D011474:Prosthesis Design; D012501:Saphenous Vein / Q000637:transplantation*; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D014481:United States
chemical_list: D020099:Coated Materials, Biocompatible; D011138:Polytetrafluoroethylene