title: Qualitative assessment of neointimal tissue after drug-eluting stent implantation: comparison between follow-up optical coherence tomography and intravascular ultrasound.
abstract: BACKGROUND
  Characterization of neointimal tissue is essential to understand the pathophysiology of in-stent restenosis after drug-eluting stent (DES) implantation. We compared the morphological characteristics of neointimal tissue as assessed by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in patients treated with DES.
  
  
  METHODS
  A total of 243 patients (250 lesions) underwent follow-up OCT and IVUS after DES implantation.
  
  
  RESULTS
  Mean time interval from DES implantation to follow-up OCT/IVUS was 12.0 ± 9.3 (range 2.8-68.5) months. Percent neointimal hyperplasia (NIH) cross-sectional area (CSA) was calculated as (NIH CSA/stent CSA) × 100 for receiver-operating characteristic analysis of NIH detection by IVUS; the optimal cutoff value of percent NIH CSA was 14.7%, as determined by OCT (sensitivity 0.887, specificity 0.790). Neointimal hyperplasia was detected by both OCT and IVUS in 121 of 250 lesions and categorized as homogenous (OCT n = 74, IVUS n = 107), heterogeneous (OCT n = 34, IVUS n = 4), or layered (OCT n = 13, IVUS n = 10). Of the 121 NIH lesions, nonhomogenous NIH was detected in 14 (11.6%) by IVUS and 47 (38.8%) by OCT. Optical coherence tomography and IVUS assessments of NIH morphology showed a moderate correlation (P < .001, r = 0.455); however, assessments differed in 37 (30.6%) of 121 lesions.
  
  
  CONCLUSIONS
  Optical coherence tomography-assessed NIH morphology might be different from that by IVUS in about 30% of the lesions that were treated with DES implantation.
authors.affiliation: Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Kwon
authors.forename: Byeong-Keuk
authors.initials: BK
authors.lastname: Kim
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Kim
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Young-Guk
authors.initials: YG
authors.lastname: Ko
authors.forename: Donghoon
authors.initials: D
authors.lastname: Choi
authors.forename: Yangsoo
authors.initials: Y
authors.lastname: Jang
authors.forename: Myeong-Ki
authors.initials: MK
authors.lastname: Hong
mesh_terms: D054855:Drug-Eluting Stents / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000000981:diagnostic imaging* / Q000473:pathology*; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D018084:Ultrasonography, Interventional