title: Morphometric assessment of coronary stenosis relevance with optical coherence tomography: a comparison with fractional flow reserve and intravascular ultrasound.
abstract: OBJECTIVE
  The study sought to assess the diagnostic efficiency of optical coherence tomography (OCT) in identifying hemodynamically severe coronary stenoses as determined by fractional flow reserve (FFR). Concomitant OCT and intravascular ultrasound (IVUS) area measurements were performed in a subgroup of patients to compare the diagnostic efficiency of both techniques.
  
  
  BACKGROUND
  The value of OCT to determine stenosis severity remains unsettled.
  
  
  METHODS
  Sixty-one stenoses with intermediate angiographic severity were studied in 56 patients. Stenoses were labeled as severe if FFR ≤0.80. OCT interrogation was performed in all cases, with concomitant IVUS imaging in 47 cases.
  
  
  RESULTS
  Angiographic stenosis severity was 50.9 ± 8% diameter stenosis with 1.28 ± 0.3 mm minimal lumen diameter. FFR was ≤0.80 in 28 (45.9%) stenoses. An overall moderate diagnostic efficiency of OCT was found (area under the curve [AUC]: 0.74; 95% confidence interval [CI]: 0.61 to 0.84), with sensitivity/specificity of 82%/63% associated with an optimal cutoff value of 1.95 mm(2). Comparison of the results in patients with simultaneous IVUS and OCT imaging revealed no significant differences in the diagnostic efficiency of OCT (AUC: 0.70; 95% CI: 0.55 to 0.83) and IVUS (AUC. 0.63; 95% CI: 0.47 to 0.77; p = 0.19). Sensitivity/specificity for IVUS was 67%/65% for an optimal cutoff value of 2.36 mm(2). In the subgroup of small vessels (reference diameter <3 mm) OCT showed a significantly better diagnostic efficiency (AUC: 0.77; 95% CI: 0.60 to 0.89) than IVUS (AUC: 0.63; 95% CI: 0.46 to 0.78) to identify functionally significant stenoses (p = 0.04).
  
  
  CONCLUSIONS
  OCT has a moderate diagnostic efficiency in identifying hemodynamically severe coronary stenoses. Although OCT seems slightly superior to IVUS for this purpose (particularly in vessels <3 mm), its low specificity precludes its use as a substitute of FFR for functional stenosis assessment.
authors.affiliation: Department of Interventional Cardiology, Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain. nieves_gonzalo@yahoo.es
authors.forename: Nieves
authors.initials: N
authors.lastname: Gonzalo
authors.forename: Nieve
authors.initials: N
authors.lastname: Gonzalo
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Fernando
authors.initials: F
authors.lastname: Alfonso
authors.forename: Christian
authors.initials: C
authors.lastname: Nolte
authors.forename: Vera
authors.initials: V
authors.lastname: Rodriguez
authors.forename: Pilar
authors.initials: P
authors.lastname: Jimenez-Quevedo
authors.forename: Camino
authors.initials: C
authors.lastname: Bañuelos
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Ortiz
authors.forename: Antonia
authors.initials: A
authors.lastname: Fernández-Ortiz
authors.forename: Eulogio
authors.initials: E
authors.lastname: Garcia
authors.forename: Rosana
authors.initials: R
authors.lastname: Hernandez-Antolin
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D000368:Aged; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence; D018084:Ultrasonography, Interventional