title: Evaluation of neointimal morphology of lesions with or without in-stent restenosis: an optical coherence tomography study.
abstract: BACKGROUND
  Characterization of neointimal tissue is essential to understand the pathophysiology of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation. Using optical coherence tomography (OCT), we compared the morphologic characteristics of in-stent neointimal tissue from 33 ISR lesions with those of 192 non-ISR lesions after DES implantation.
  
  
  OBJECTIVE
  We hypothesized that the morphologic characteristics of in-stent neointimal tissue from ISR lesions were different from those of non-ISR lesions after DES implantation.
  
  
  METHODS
  The DES were coated with sirolimus (n=52), paclitaxel (n=57), zotarolimus (n=84), or everolimus (n=32). In-stent restenosis was defined as ≥50% diameter stenosis at the follow-up angiogram. Lesions with ≥10% neointimal burden ([neointima area × 100]/[stent area]), as determined by OCT, were included in this study. A follow-up OCT (mean follow-up duration, 12.0 ± 10.5 mo) was performed in 209 patients with 225 lesions (ISR lesions, n=33; non-ISR lesions, n=192). Qualitative OCT was used to assess tissue structure, backscatter, visible microvessels, and presence of intraluminal material.
  
  
  RESULTS
  The following characteristics were more common in ISR lesions than in non-ISR lesions: heterogeneous or layered tissues (78.8% vs 22.9%, P<0.001), low backscatter (60.6% vs 20.8%, P<0.001), and microvessels (48.5% vs 5.7%, P<0.001). The independent predictors for heterogeneous or layered neointimal tissues were increased neointima burden (odds ratio [OR]: 1.218, 95% confidence interval [CI]: 1.096-1.354, P<0.001), lumen area (OR: 4.672, 95% CI: 1.371-15.914, P = 0.014), and hypertension (OR: 0.415, 95% CI: 0.186-0.926, P = 0.032).
  
  
  CONCLUSIONS
  This follow-up OCT study demonstrated that morphologic characteristics of neointimal tissues of ISR lesions differ from those of non-ISR lesions.
authors.affiliation: Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Sung-Joo
authors.initials: SJ
authors.lastname: Lee
authors.forename: Byeong-Keuk
authors.initials: BK
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: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012042:Registries; D056910:Republic of Korea; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D017539:Tunica Intima / Q000473:pathology*