title: Optical coherence tomography evaluation of in-stent restenotic lesions with visible microvessels.
abstract: OBJECTIVE
  We sought to evaluate the characteristics of in-stent restenosis (ISR) lesions with microvessels, detected by an optical coherence tomography (OCT).
  
  
  BACKGROUND
  No sufficient in vivo data exist regarding microvessel characteristics in ISR lesions.
  
  
  METHODS
  Among 78 ISR lesions (drug-eluting stent, n = 72; bare-metal stent, n = 6) in our OCT registry database, visible microvessels were detected in 21 (27%). Microvessels were defined as low backscattering structures <200 μm in diameter on OCT. Clinical, angiographic, and OCT findings were compared between lesions with and without microvessels.
  
  
  RESULTS
  Lesions with microvessels had a larger reference vessel diameter (2.90 ± 0.47 mm vs 2.58 ± 0.42 mm; P=.009) and post-stent minimum lumen diameter (2.76 ± 0.29 mm vs 2.54 ± 0.39 mm; P=.033) than those without microvessels. From OCT findings at the segment with minimal lumen cross-sectional area (CSA), neointimal hyperplasia (NIH) CSA (5.4 ± 1.7 mm² vs 4.2 ± 2.1 mm²; P=.024) and percent NIH CSA (NIH CSA x 100/stent CSA) were significantly greater in lesions with microvessels (79 ± 12% vs 67 ± 16%; P=.001). On multivariate analysis, reference vessel diameter (odds ratio [OR], 4.64; 95% confidence interval [CI], 1.05-20.4; P=.043) and percent NIH CSA at the segment with minimal lumen CSA (OR, 1.06; 95% CI, 1.01-1.12; P=.021) were independent predictors of microvessels. From receiver operating characteristic analysis, the cut-off values of reference vessel diameter and percent NIH CSA predicting the presence of microvessels were 3.1 mm and 74%, respectively.
  
  
  CONCLUSIONS
  Visible microvessels in ISR lesions might be associated with increased vessel size and extent of NIH.
authors.affiliation: Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Byeong-Keuk
authors.initials: BK
authors.lastname: Kim
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Shin
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: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D023903:Coronary Restenosis / Q000473:pathology*; D023921:Coronary Stenosis / Q000628:therapy; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055806:Microvessels / Q000473:pathology*; D008875:Middle Aged; D058426:Neointima / Q000473:pathology; D012372:ROC Curve; D015607:Stents; D041623:Tomography, Optical Coherence / Q000379:methods*