title: Evaluation of hemodynamically severe coronary stenosis as determined by fractional flow reserve with frequency domain optical coherence tomography measured anatomical parameters.
abstract: OBJECTIVE
  The main objective of this study is to determine the correlation between fractional flow reserve (FFR)- and frequency domain optical coherence tomography (FD-OCT)-measured lumen parameters, and to determine the diagnostic competence of FD-OCT concerning the identification of severe coronary stenosis.
  
  
  METHODS
  A total of 41 coronary stenoses in 30 patients were assessed consecutively by quantitative coronary angiography (QCA), FFR, and FD-OCT. Stenoses were labeled severe if FFR ≤ 0.80. The minimal lumen area (MLA), minimal lumen diameter (MLD), and percent lumen area stenosis (%AS) were measured using FD-OCT.
  
  
  RESULTS
  FFR was ≤ 0.80 in 10 stenoses (24.4%). A poor but significant correlation between FFR and FD-OCT-measured MLA (r(2) = 0.4, p < 0.001), MLD (r(2) = 0.28, p < 0.001), and %AS (r(2) = 0.13, p = 0.02) was found. In the overall group, the diagnostic efficiency of MLA and MLD in identifying significant stenosis was moderate. The area under the curve (AUC) was 0.80 [95% confidence interval (CI): 0.64-0.91] for MLA and 0.76 (95% CI: 0.60-0.88) for MLD. The best cut-off values of FD-OCT-measured lumen parameters to identify stenosis with FFR ≤ 0.80 were 1.62 mm(2) [specificity 97%, sensitivity 70%, positive predictive value (PPV) 89% and negative predictive value (NPV) 91%] for MLA and 1.23 mm (specificity 87%, sensitivity 70%, PPV 64% and NPV 90%) for MLD. The diagnostic efficiency of MLA in identifying significant stenosis in vessels having reference diameter < 3 mm was high. The AUC was 0.96 (95% CI: 0.83-1.0).
  
  
  CONCLUSIONS
  The FFR values and FD-OCT anatomical parameters MLA, MLD were found to be significantly correlated. In the overall group, the FD-OCT-measured MLA and MLD have shown moderate diagnostic efficiency in the functional evaluation of significant stenosis. FD-OCT-measured MLA has high diagnostic efficiency in identifying severe coronary stenosis in vessels having reference diameter < 3 mm.
authors.affiliation: Tissue Optics & Microcirculation Imaging Facility, National University of Ireland, Galway, Ireland; National Biophotonics & Imaging Platform, Dublin, Ireland. Electronic address: h.zafar1@nuigalway.ie.
authors.forename: Haroon
authors.initials: H
authors.lastname: Zafar
authors.affiliation: Department of Cardiology, University Hospital Galway, Ireland.
authors.forename: Ihsan
authors.initials: I
authors.lastname: Ullah
authors.affiliation: Department of Cardiology, University Hospital Galway, Ireland.
authors.forename: Kate
authors.initials: K
authors.lastname: Dinneen
authors.affiliation: Department of Cardiology, University Hospital Galway, Ireland.
authors.forename: Sajjad
authors.initials: S
authors.lastname: Matiullah
authors.affiliation: Department of Cardiology, University Hospital Galway, Ireland.
authors.forename: Alan
authors.initials: A
authors.lastname: Hanley
authors.affiliation: Tissue Optics & Microcirculation Imaging Facility, National University of Ireland, Galway, Ireland; National Biophotonics & Imaging Platform, Dublin, Ireland; Royal College of Surgeons, Dublin, Ireland.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Leahy
authors.affiliation: Department of Cardiology, University Hospital Galway, Ireland; HRB Clinical Research Facility, Galway, Ireland; Regenerative Medicine Institute, National University of Ireland, Galway, Ireland; Bio Innovate, Ireland.
authors.forename: Faisal
authors.initials: F
authors.lastname: Sharif
mesh_terms: D000368:Aged; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence
keywords: Coronary stenosis; Fractional flow reserve; Frequency domain optical coherence tomography; Minimal lumen area; Minimal lumen diameter