title: Intravascular ultrasound results from the ENDEAVOR IV trial: randomized comparison between zotarolimus- and paclitaxel-eluting stents in patients with coronary artery disease.
abstract: OBJECTIVE
  The aim of this study was to compare the vessel response between zotarolimus-eluting stents (ZES) and paclitaxel-eluting stents (PES) using intravascular ultrasound.
  
  
  BACKGROUND
  The ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial was a randomized controlled study of zotarolimus-eluting, phosphorylcholine-coated, cobalt-alloy stents for the treatment of de novo coronary lesions compared with using PES for the same treatment.
  
  
  METHODS
  Data were obtained from patients with serial (baseline and 8-months follow-up) intravascular ultrasound analysis available (n = 198). Volumetric analysis was performed for vessel, lumen, plaque, stent, and neointima. Cross-sectional narrowing (given as percentage) was defined as neointimal area divided by stent area. Neointima-free frame ratio was calculated as the number of frames without intravascular ultrasound-detectable neointima divided by the total number of frames within the stent. Subsegment analysis was performed at every matched 1-mm subsegment throughout the stent.
  
  
  RESULTS
  At follow-up, the ZES group showed significantly greater percentage of neointimal obstruction (16.6 +/- 12.0% vs. 9.9 +/- 8.9%, p < 0.01) and maximum cross-sectional narrowing (31.8 +/- 16.1% vs. 25.2 +/- 14.9%, p < 0.01) with smaller minimum lumen area than the PES group did. However, the incidence of maximum cross-sectional narrowing >50% was similar in the 2 groups. Neointima-free frame ratio was significantly lower in the ZES group. In overall analysis, whereas the PES group showed positive remodeling during follow-up (13.7 +/- 4.2 mm(3)/mm to 14.3 +/- 4.3 mm(3)/mm), the ZES group showed no significant difference (12.7 +/- 3.6 mm(3)/mm to 12.9 +/- 3.5 mm(3)/mm). In subsegment analysis, significant focal positive vessel remodeling was observed in 5% of ZES and 25% of PES cases (p < 0.05).
  
  
  CONCLUSIONS
  There were different global and focal vessel responses for ZES and PES. Both drug-eluting stents showed a similar incidence of lesions with severe narrowing despite ZES having a moderate increase in neointimal hyperplasia compared with neointimal hyperplasia in PES. There was a relatively lower neointima-free frame ratio in ZES, suggesting a greater extent of neointimal coverage. (The ENDEAVOR IV Clinical Trial: A Trial of a Coronary Stent System in Coronary Artery Lesions; NCT00217269).
authors.affiliation: Center for Cardiovascular Technology, Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305, USA.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Miyazawa
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Takao
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Ichizo
authors.initials: I
authors.lastname: Tsujino
authors.forename: Ryota
authors.initials: R
authors.lastname: Sakurai
authors.forename: Paul G
authors.initials: PG
authors.lastname: Yock
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
authors.forename: David E
authors.initials: DE
authors.lastname: Kandzari
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
mesh_terms: D000368:Aged; D000497:Alloys; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D020099:Coated Materials, Biocompatible; D003035:Cobalt; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D017239:Paclitaxel / Q000008:administration & dosage*; D010767:Phosphorylcholine; D011474:Prosthesis Design; D016037:Single-Blind Method; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional; D014481:United States
chemical_list: D000497:Alloys; D002317:Cardiovascular Agents; D020099:Coated Materials, Biocompatible; D010767:Phosphorylcholine; D003035:Cobalt; C489443:zotarolimus; D017239:Paclitaxel; D020123:Sirolimus