Intravascular ultrasound results from the ENDEAVOR IV trial: randomized comparison between zotarolimus- and paclitaxel-eluting stents in patients with coronary artery disease

JACC Cardiovasc Interv. 2009 Aug;2(8):779-84. doi: 10.1016/j.jcin.2009.05.015.


Objectives: 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).

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alloys
  • Angioplasty, Balloon, Coronary / adverse effects
  • Angioplasty, Balloon, Coronary / instrumentation*
  • Cardiovascular Agents / administration & dosage*
  • Coated Materials, Biocompatible
  • Cobalt
  • Coronary Artery Disease / diagnostic imaging*
  • Coronary Artery Disease / therapy*
  • Coronary Restenosis / diagnostic imaging
  • Coronary Restenosis / etiology
  • Coronary Restenosis / prevention & control
  • Drug-Eluting Stents*
  • Female
  • Humans
  • Hyperplasia
  • Male
  • Middle Aged
  • Paclitaxel / administration & dosage*
  • Phosphorylcholine
  • Prosthesis Design
  • Single-Blind Method
  • Sirolimus / administration & dosage
  • Sirolimus / analogs & derivatives*
  • Time Factors
  • Treatment Outcome
  • Tunica Intima / diagnostic imaging
  • Ultrasonography, Interventional*
  • United States


  • Alloys
  • Cardiovascular Agents
  • Coated Materials, Biocompatible
  • Phosphorylcholine
  • Cobalt
  • zotarolimus
  • Paclitaxel
  • Sirolimus

Associated data