title: An intravascular ultrasound study of Cypher, Taxus, and endeavor stents on relation between neointimal proliferation and residual plaque burden.
abstract: BACKGROUND
  Studies on balloon angioplasty, atherectomy, and bare metal stent have shown a direct relation between residual plaque burden and restenosis. We investigated the relation between residual plaque burden and neointimal proliferation after drug-eluting stent (DES) implantation.
  
  
  METHODS
  Over a period of 12 months, 65 patients (Cypher, n = 25; Taxus, n = 28; Endeavor, n = 12) from two centers underwent intravascular ultrasound (IVUS) examination at 8.2 (interquartile range 6.8-9.5) months after coronary stent implantation in native de novo coronary arteries. IVUS images were acquired with motorized pullback at 0.5 mm/s, and cross-sectional measurements were performed within the stents at 1-mm intervals. The following measurements were obtained: (1) lumen area (LA), (2) stent area (SA), (3) external elastic membrane area (EEMA), (4) percent neointimal hyperplasia area (SA-LA/SA) x 100, and (5) percent residual plaque area (EEMA-SA)/EEMA x 100.
  
  
  RESULTS
  The analysis of 1,173 cross sections (Cypher, n = 436; Taxus, n = 532, Endeavor, n = 205) using mixed model to account for intrasubject correlation showed an absence of relation between percent residual plaque area and percent neointimal hyperplasia area (P = 0.189). Mean residual plaque burden outside the stent for Cypher, Taxus, and Endeavor groups was similar (45.7%, 44.8%, and 42.4%, respectively). Mean percent neointimal hyperplasia area for the Cypher, Taxus, and Endeavor groups was 12.0%, 15.0%, and 16.2%, respectively (P = 0.163).
  
  
  CONCLUSIONS
  In patients after first-generation DES implantation and without significant in-stent restenosis, late in-stent neointimal proliferation is not related to the amount of residual plaque burden after stent implantation. This suggests against routine plaque removal before DES implantation to reduce neointimal proliferation.
authors.affiliation: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. mdclchr@nus.edu.sg
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Lee
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.forename: Anand
authors.initials: A
authors.lastname: Kailasam
authors.forename: Bee-Choo
authors.initials: BC
authors.lastname: Tai
authors.forename: Fei
authors.initials: F
authors.lastname: Ye
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Low
authors.forename: Xumin
authors.initials: X
authors.lastname: Hou
authors.forename: Edourdo Tin
authors.initials: ET
authors.lastname: Hay
authors.forename: Swee-Guan
authors.initials: SG
authors.lastname: Teo
authors.forename: Yean-Teng
authors.initials: YT
authors.lastname: Lim
authors.forename: Shaoliang
authors.initials: S
authors.lastname: Chen
authors.forename: Huay-Cheem
authors.initials: HC
authors.lastname: Tan
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D016208:Databases, Factual; D054855:Drug-Eluting Stents; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020946:Taxus; D014463:Ultrasonography