title: Intravascular ultrasound insights from the Cobalt Chromium Stent With Antiproliferative for Restenosis II (COSTAR II) trial comparing CoStar and Taxus paclitaxel-eluting stents.
abstract: BACKGROUND
  Dedicated IVUS analyses of the second CObalt chromium STent with Antiproliferative for Restenosis (COSTAR II) trial have not been documented. We aim to compare IVUS findings between CoStar paclitaxel-eluting stent (PES) and Taxus PES in patients enrolled in the COSTAR II trial. We also attempted to examine the possible regional impact of multiple stenting.
  
  
  METHODS
  Among the 1700 patients enrolled, 238 were assigned to an IVUS cohort including 168 patients treated by provisional multiple stenting. At 9 months, qualitative and quantitative IVUS observations including incomplete stent apposition (ISA) and neointimal proliferation (neointimal obstruction: neointimal volume/stent volume ×100) were compared between CoStar and Taxus PESs.
  
  
  RESULTS
  In qualitative analysis, late-acquired ISA was observed in 1 patient treated by Taxus PES. Impaired strut continuity suggestive of stent fracture was observed in 2 out of 33 patients treated by multiple CoStar, and 4 out of 21 patients treated by multiple Taxus (P=.14). No such findings were found in single-stented patients in either stent subset. Quantitative analysis showed greater neointimal obstruction in CoStar (19.7%±13.4%, n=52) than in Taxus (10.7%±9.9%, n=38), whereas no significant difference in neointimal obstruction was found between single and multiple stenting in either CoStar or Taxus PES.
  
  
  CONCLUSIONS
  The CoStar PES exhibits greater neointimal proliferation compared with Taxus PES at 9 months but with similar qualitative outcomes including late-acquired ISA. IVUS findings suggestive of stent fracture were found only in multiple-stenting cases irrespective of the stent used.
authors.affiliation: Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, CA 94305, USA.
authors.forename: Ichizo
authors.initials: I
authors.lastname: Tsujino
authors.forename: Tomomi
authors.initials: T
authors.lastname: Koizumi
authors.forename: Takao
authors.initials: T
authors.lastname: Shimohama
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Mitchell
authors.initials: M
authors.lastname: Krucoff
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D002858:Chromium Alloys; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000601:surgery*; D023903:Coronary Restenosis / Q000517:prevention & control*; D054855:Drug-Eluting Stents; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000000981:diagnostic imaging / Q000517:prevention & control*; D017239:Paclitaxel / Q000494:pharmacology*; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016037:Single-Blind Method; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002858:Chromium Alloys; D017239:Paclitaxel