title: In vivo comparison between optical coherence tomography and intravascular ultrasound for detecting small degrees of in-stent neointima after stent implantation.
abstract: OBJECTIVE
  The purpose of this study was to evaluate optical coherence tomography (OCT) for detecting small degrees of in-stent neointima (ISN) after stent implantation compared with intravascular ultrasound (IVUS).
  
  
  BACKGROUND
  The importance of detecting neointimal coverage of stent struts has grown with the appreciation of the increased risk for late stent thrombosis after drug-eluting stent (DES) implantation. Intravascular ultrasound, the current standard for evaluating the status of DES, lacks the resolution to detect the initial neointimal coverage. Optical coherence tomography has greater resolution but has not yet been compared with IVUS in vivo with histological correlation for validation.
  
  
  METHODS
  Intravascular ultrasound and OCT were performed with motorized pullback imaging in 6 pigs across 33 stents, 1 month after implantation. Each pig was euthanized, and histological measurements of vessel, stent, and lumen dimensions were performed in 3 sections of each stent. A small degree of ISN was defined as occupying <30% of the stent area measured with histology. The IVUS, OCT, and histological assessment of ISN were compared in matched cross-sections of the stents with a small degree of ISN.
  
  
  RESULTS
  Eleven stents had a small degree of ISN (average ISN area: 1.26 +/- 0.46 mm(2), and percent area obstruction: 21.4 +/- 5.2%). Compared with histology, the diagnostic accuracy of OCT (area under the receiver operating characteristic curve [AUC] = 0.967, 95% confidence interval [CI] 0.914 to 1.019) was higher than that of IVUS (AUC = 0.781, 95% CI 0.621 to 0.838).
  
  
  CONCLUSIONS
  Optical coherence tomography detects smaller degrees of ISN more accurately than IVUS and might be a useful method for identifying neointimal coverage of stent struts after DES implantation.
authors.affiliation: Division of Cardiovascular Medicine, Stanford University, Stanford, California, USA.
authors.forename: Yoriyasu
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ikeno
authors.forename: Tomomi
authors.initials: T
authors.lastname: Koizumi
authors.forename: Fermin
authors.initials: F
authors.lastname: Tio
authors.forename: Alan C
authors.initials: AC
authors.lastname: Yeung
authors.forename: Paul G
authors.initials: PG
authors.lastname: Yock
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: William F
authors.initials: WF
authors.lastname: Fearon
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D000818:Animals; D023903:Coronary Restenosis / Q000175:diagnosis* / Q000209:etiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology*; D023421:Models, Animal; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D015607:Stents; D013552:Swine; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology; D018084:Ultrasonography, Interventional