title: Neointimal patterns obtained by optical coherence tomography correlate with specific histological components and neointimal proliferation in a swine model of restenosis.
abstract: OBJECTIVE
  Although optical coherence tomography (OCT) is capable to detect microscopic peri-strut changes that seem to be related to neointimal inhibition and healing, its ability to characterize these components is still limited. In this study, we aimed to compare different OCT morphological characteristics with different in-stent neointimal tissue types analysed by histology.
  
  
  METHODS
  A total of 69 stents (39 drug eluting and 30 bare metal stents) were implanted in coronary arteries of 27 swine. By OCT, neointimal type was classified as homogeneous, heterogeneous, or layered according to its pattern of backscatter and optical intensity. The resulting optical patterns were correlated with several histological findings [external elastic lamina (EEL) disruption, fibrin deposition, circumferential rim of peri-strut inflammatory cell infiltration, and fibrous connective deposition] in every single cross-section (CS) analysed.
  
  
  RESULTS
  A total of 197 matched OCT and histological CS were analysed. The heterogeneous (0.44 ± 0.21 mm) and layered (0.65 ± 0.16 mm) patterns had a significantly higher degree of neointimal thickness compared with the homogeneous pattern (0.25 ± 0.16 mm, P < 0.001). Fibrous connective tissue deposition was more frequently present in the homogeneous pattern (71.6%, P < 0.001), whereas significant fibrin deposits were more commonly seen in the heterogeneous pattern (56.9%, P = 0.007). Peri-strut inflammation was less frequently found in the homogeneous pattern (19.8%, P < 0.001) in comparison with the layered (73.9%) or heterogeneous patterns (43.1%). The presence of EEL rupture was also more commonly seen in layered (73.9%) and heterogeneous (46.6%) patterns than in the homogeneous pattern (22.4%, P < 0.001).
  
  
  CONCLUSIONS
  The optical characteristics of neointimal formation seen in OCT properly correlated with the presence of several histological findings involved in stent healing. The biological implications of these findings in clinical outcomes require further investigation.
authors.affiliation: Skirball Center for Cardiovascular Research, Cardiovascular Research Foundation, 8 Corporate Drive, Orangeburg, NY 10962, USA.
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Maxwell E
authors.initials: ME
authors.lastname: Afari
authors.forename: Jinyong
authors.initials: J
authors.lastname: Ha
authors.forename: Armando
authors.initials: A
authors.lastname: Tellez
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Milewski
authors.forename: Gerard
authors.initials: G
authors.lastname: Conditt
authors.forename: Yanping
authors.initials: Y
authors.lastname: Cheng
authors.forename: Geng
authors.initials: G
authors.lastname: Hua Yi
authors.forename: Greg L
authors.initials: GL
authors.lastname: Kaluza
authors.forename: Juan F
authors.initials: JF
authors.lastname: Granada
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D000818:Animals; D001707:Biopsy, Needle; D049109:Cell Proliferation; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000473:pathology*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000628:therapy; D004195:Disease Models, Animal; D054855:Drug-Eluting Stents; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D008670:Metals; D058426:Neointima / Q000000981:diagnostic imaging / Q000473:pathology*; D011897:Random Allocation; D015607:Stents; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D008670:Metals
keywords: Histology; Neointima; Optical coherence tomography; Optical intensity; Stent