title: Intra- and interobserver reliability and intra-catheter reproducibility using frequency domain optical coherence tomography for the evaluation of morphometric stent parameters and qualitative assessment of stent strut coverage.
abstract: OBJECTIVE
  Frequency-domain optical coherence tomography (FD-OCT) is a high-resolution imaging tool (~10-15 μm), which enables near-histological in-vivo images of the coronary vessel wall. The use of the technique is increasing, both for research- and clinical purposes. This study sought to investigate the intra- and interobserver reliability, as well as the intra-catheter reproducibility of quantitative FD-OCT-assessment of morphometric stent parameters and qualitative FD-OCT-evaluation of strut coverage in 10 randomly selected 6-month follow-up Nobori® biolimus-eluting stents (N-BESs).
  
  
  METHODS
  Ten N-BESs (213 cross sectional areas (CSAs) and 1897 struts) imaged with OCT 6 months post-implantation were randomly selected and analyzed by 2 experienced analysts, and the same 10 N-BESs were analyzed by one of the analysts 3 months later. Further, 2 consecutive pullbacks randomly performed in another 10 N-BESs (219 CSAs and 1860 struts) were independently assessed by one of the analysts.
  
  
  RESULTS
  The intraobserver variability with regard to relative difference of mean luminal area and mean stent area at the CSA-level was very low: 0.1%±1.4% and 0.5%±3.2%. Interobserver variability also proved to be low: -2.1%±3.3% and 2.1%±4.6%, and moreover, very restricted intra-catheter variation was observed: 0.02%±6.8% and -0.18%±5.2%. The intraobserver-, interobserver- and intra-catheter reliability for the qualitative evaluation of strut coverage was found to be: kappa (κ)=0.91 (95% confidence interval (CI): 0.88-0.93, p<0.01), κ=0.88 (95% CI: 0.85-0.91, p<0.01), and κ=0.73 (95% CI: 0.68-0.78, p<0.01), respectively.
  
  
  CONCLUSIONS
  FD-OCT is a reproducible and reliable imaging tool for quantitative evaluation of stented coronary segments, and for qualitative assessment of strut coverage.
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark. Electronic address: Lisbeth.antonsen@rsyd.dk.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Antonsen
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Thayssen
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Junker
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Karsten Tange
authors.initials: KT
authors.lastname: Veien
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Henrik Steen
authors.initials: HS
authors.lastname: Hansen
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Knud Nørregaard
authors.initials: KN
authors.lastname: Hansen
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Hougaard
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Lisette Okkels
authors.initials: LO
authors.lastname: Jensen
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D003718:Denmark; D054855:Drug-Eluting Stents; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011474:Prosthesis Design; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D015203:Reproducibility of Results; D018570:Risk Assessment; D012720:Severity of Illness Index; D020123:Sirolimus / Q000494:pharmacology; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*; D016896:Treatment Outcome; D014654:Vascular Patency / Q000502:physiology
chemical_list: D020123:Sirolimus
keywords: Optical coherence tomography; Reproducibility; Stent morphometry; Stent strut coverage