title: Quantitative analysis of the side-branch orifice after bifurcation stenting using en-face processing of OCT images: a comparison between Xience V and Resolute Integrity stents.
abstract: OBJECTIVE
  Methods for intravascular assessment of the side-branch (SB) orifice after stenting are not readily available. The aim of this study was to assess the utility of an en-face projection processing for optical coherence tomography (OCT) images for SB evaluation.
  
  
  METHODS
  Measurements of the SB orifice obtained using en-face OCT images were validated using a phantom model. Linear regression modeling was applied to estimated area measurements made on the en-face images. The SB orifice was then analyzed in 88 patients with bifurcation lesions treated with either Xience V (everolimus-eluting stent) or Resolute Integrity [zotarolimus-eluting stent (ZES)]. The SB orifice area (A) and the area obstructed by struts (B) were calculated, and the %open area was evaluated as (A-B)/A*100.
  
  
  RESULTS
  Linear regression modeling demonstrated that the observed departures of the intercept and slope were not significantly different from 0 (-0.12 ± 0.22, P=0.59) and 1 (1.01 ± 0.06, R(2)=0.88, P=0.87), respectively. In cases without SB dilatation, the %open area was significantly larger in the everolimus-eluting stent group (n=25) than in the ZES group [n=32; 89.2% (83.7-91.3) vs. 84.3% (78.9-87.8), P=0.04]. A significant difference in %open area between cases with and those without SB dilatation was demonstrated in the ZES group [91.4% (86.1-94.0) vs. 84.3% (78.9-87.8), P=0.04].
  
  
  CONCLUSIONS
  The accuracy of SB orifice measurement on an en-face OCT image was validated using a phantom model. This novel approach enables quantitative evaluation of the differences in SB orifice area free from struts among different stent types and different treatment strategies in vivo.
authors.affiliation: aCardiology Division bBiostatistics Center, Massachusetts General Hospital cCardiology Division, Brigham and Women's Hospital, Harvard Medical School, Boston dResearch Laboratory of Electronics, Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA eQueen Mary Hospital, Hong Kong University, Pok Fu Lam, Hong Kong fCardiology Division, Kawasaki Medical University, Okayama Prefecture gIwate Medical University, Morioka, Japan hPrince Charles Hospital, Queensland iThe University of Melbourne, Melbourne, Australia jDivision of Cardiology, Kyung Hee University, Seoul, South Korea.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Minami
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Aguirre
authors.forename: Stephen
authors.initials: S
authors.lastname: Lee
authors.forename: Shiro
authors.initials: S
authors.lastname: Uemura
authors.forename: Tsunenari
authors.initials: T
authors.lastname: Soeda
authors.forename: Rocco
authors.initials: R
authors.lastname: Vergallo
authors.forename: Owen C
authors.initials: OC
authors.lastname: Raffel
authors.forename: Peter
authors.initials: P
authors.lastname: Barlis
authors.forename: Tomonori
authors.initials: T
authors.lastname: Itoh
authors.forename: Hang
authors.initials: H
authors.lastname: Lee
authors.forename: James
authors.initials: J
authors.lastname: Fujimoto
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
mesh_terms: D001672:Biocompatible Materials; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis / Q000601:surgery*; D003331:Coronary Vessels / Q000473:pathology* / Q000601:surgery; D054855:Drug-Eluting Stents; D000068338:Everolimus / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D019047:Phantoms, Imaging; D011098:Polyglactin 910; D011474:Prosthesis Design; D015203:Reproducibility of Results; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; C094810:Resolut; D011098:Polyglactin 910; D000068338:Everolimus; C489443:zotarolimus; D020123:Sirolimus