title: Ex vivo assessment of neointimal characteristics after drug-eluting stent implantation: Optical coherence tomography and histopathology validation study.
abstract: BACKGROUND
  Optical coherence tomography (OCT) is one of the tools trying to distinguish neoatherosclerosis from other neointimal tissue but its role has to be still validated. This study evaluated the diagnostic accuracy of OCT for characterization of lipid-atherosclerotic neointima following drug-eluting stent (DES) implantation.
  
  
  METHODS
  Twelve stented coronary arteries from the 7 autopsy hearts were imaged by OCT. These OCT images were compared with histology. By OCT, the morphological appearances of neointima were classified into three patterns: homogeneous pattern, heterogeneous pattern with visible strut, or heterogeneous pattern with invisible strut.
  
  
  RESULTS
  Of 21 histological cross-sections, 6 were categorized as homogeneous patterns (29%), 11 as heterogeneous patterns with visible stent strut (52%), and 4 as heterogeneous patterns with invisible stent strut (19%). All homogeneous patterns were composed of smooth muscle cells with collagen fibers. The heterogeneous patterns with visible stent strut included proteoglycan-rich myxomatous matrix and calcium deposition. On the other hand, the heterogeneous patterns with invisible stent strut comprised atheromatous tissue, including a large amount of foam cell accumulation (25%) or large fibroatheroma/necrotic core (75%) inside the stent struts within neointima. The optical attenuation coefficient was highest in the heterogeneous pattern with invisible stent strut due to scattering of light by atheromatous tissue.
  
  
  CONCLUSIONS
  The heterogeneous patterns with invisible stent strut on OCT imaging identify the presence of lipid-atherosclerotic tissue within neointima after DES. This may suggest the potential capability of OCT based on visualization of stent struts for discriminating atheromatous formation within neointima from other neointimal tissue.
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Imanaka
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan. Electronic address: kfujii350@hotmail.com.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.affiliation: Department of Pathology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hao
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shibuya
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Ten
authors.initials: T
authors.lastname: Saita
authors.affiliation: Department of Surgical Pathology, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Kawakami
authors.affiliation: Cardiovascular Division, Morinomiya Hospital, Osaka, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukunaga
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawai
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Tamaru
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Miki
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Horimatsu
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Sumiyoshi
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Department of Surgical Pathology, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hirota
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Masuyama
authors.affiliation: Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ishihara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000175:diagnosis / Q000209:etiology; D001344:Autopsy; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D061827:Dimensional Measurement Accuracy; D054855:Drug-Eluting Stents / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000000981:diagnostic imaging / Q000473:pathology; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Drug-eluting stent; Histology; Optical coherence tomography