title: Evolving concepts of angiogram: fractional flow reserve discordances in 4000 coronary stenoses.
abstract: OBJECTIVE
  The present analysis addresses the potential clinical and physiologic significance of discordance in severity of coronary artery disease between the angiogram and fractional flow reserve (FFR) in a large and unselected patient population.
  
  
  RESULTS
  Between September 1999 and December 2011, FFR and percent diameter stenosis (DS) as assessed by quantitative coronary angiography were obtained in 2986 patients (n = 4086 coronary stenoses), in whom at least one stenosis was of intermediate angiographic severity. Fractional flow reserve correlated slightly but significantly with DS [-0.38 (95% CI: -0.41; -0.36); P < 0.001]. The sensitivity, specificity, and diagnostic accuracy of a ≥ 50% DS for predicting FFR ≤ 0.80 were 61% (95% CI: 59; 63), 67% (95% CI: 65; 69), and 0.64 (95% CI: 0.56; 0.72), respectively. In different anatomical settings, sensitivity and specificity showed marked variations between 35 to 74% and 58 to 76%, respectively, resulting in a discordance in 35% of all cases for these thresholds. For an angiographic threshold of 70% DS, the diagnostic performance by the Youden's index decreased from 0.28 to 0.11 for the overall population.
  
  
  CONCLUSIONS
  The data confirm that one-third of a large patient population shows discordance between angiogram ≥ 50%DS and FFR ≤ 0.8 thresholds of stenosis severity. Left main stenoses are often underestimated by the classical 50% DS cut-off compared with FFR. This discordance offers physiologic insights for future trials. It is hypothesized that the discordance between angiography and FFR is related to technical limitations, such as imprecise luminal border detection by angiography, as well as to physiologic factors, such as variable minimal microvascular resistance.
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Gabor
authors.initials: G
authors.lastname: Toth
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Michalis
authors.initials: M
authors.lastname: Hamilos
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Stylianos
authors.initials: S
authors.lastname: Pyxaras
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Fabio
authors.initials: F
authors.lastname: Mangiacapra
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Nelis
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Frederic
authors.initials: F
authors.lastname: De Vroey
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Serafino
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Muller
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Carlos
authors.initials: C
authors.lastname: Van Mieghem
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Wyffels
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Guy R
authors.initials: GR
authors.lastname: Heyndrickx
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Bartunek
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Vanderheyden
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Barbato
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium.
authors.forename: William
authors.initials: W
authors.lastname: Wijns
authors.affiliation: Cardiovascular Center Aalst, OLV-Clinic, Moorselbaan, 164, B-9300 Aalst, Belgium bernard.de.bruyne@olvz-aalst.be.
authors.forename: Bernard
authors.initials: B
authors.lastname: De Bruyne
mesh_terms: D000368:Aged; D019540:Area Under Curve; D017023:Coronary Angiography / Q000379:methods / Q000592:standards; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology*; D006801:Humans; D007548:Isosorbide Dinitrate; D008297:Male; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014655:Vascular Resistance / Q000502:physiology; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate
keywords: Coronary artery disease; Fractional flow reserve; Quantitative coronary angiography