title: Effect of strut thickness on neointimal atherosclerotic change over an extended follow-up period (≥ 4 years) after bare-metal stent implantation: intracoronary optical coherence tomography examination.
abstract: BACKGROUND
  Neointima inside the bare-metal stents (BMSs) can transform into atherosclerotic tissue during an extended follow-up because of a persistent inflammatory reaction to the metal. We sought to investigate whether strut thickness may impact on the atherosclerotic change in neointima 4 years or more after BMS implantation using optical coherence tomography.
  
  
  METHODS
  Forty-six stented lesions of 41 patients with BMS ≥ 4 years after implantation who underwent optical coherence tomography were enrolled in the study. The strut was defined as thin when less than 100 μm and thick when ≥ 100 μm. According to these criteria, stents were divided into 2 groups (thin strut n = 19, thick strut n = 27). Neointimal tissue was categorized into normal neointima, characterized by a signal-rich band without signal attenuation, or lipid-laden intima, with marked signal attenuation and a diffuse border. Intimal disruption, thrombus, and neovascularization were also evaluated.
  
  
  RESULTS
  The mean period after implantation was 98.2 ± 25.8 months in the thin-strut group and 91.1 ± 22.8 months in the thick-strut group (P = .330). Lipid-laden intima (70% vs 32%, P = .016), thin-cap fibroatheroma-like intima (59% vs 16%, P = .0056), and intimal disruption (48% vs 16%, P = .031) were observed more frequently in the thick-strut group than in the thin-strut group, but no significant difference was observed in the frequency of thrombus. Although peristrut neovascularization was a common finding in both groups (thick vs thin 81% vs 79%, P = 1.000), the frequency of intraintima neovascularization tended to be higher in the thick-strut group (67% vs 42%, P = .135).
  
  
  CONCLUSIONS
  A thinner strut thickness may have favorable effects on neointimal atherosclerotic changes after BMS implantation.
authors.affiliation: Department of Cardiovascular Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Kitabata
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.forename: Kenichi
authors.initials: K
authors.lastname: Komukai
authors.forename: Kohei
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ino
authors.forename: Shigeho
authors.initials: S
authors.lastname: Takarada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Manabu
authors.initials: M
authors.lastname: Kashiwagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Orii
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Shiono
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Shiono
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Shimamura
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hirata
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Keizo
authors.initials: K
authors.lastname: Kimura
authors.forename: Masato
authors.initials: M
authors.lastname: Mizukoshi
authors.forename: Toshio
authors.initials: T
authors.lastname: Imanishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000473:pathology*; D011474:Prosthesis Design; D015607:Stents; D041623:Tomography, Optical Coherence