title: Fast virtual functional assessment of intermediate coronary lesions using routine angiographic data and blood flow simulation in humans: comparison with pressure wire - fractional flow reserve.
abstract: OBJECTIVE
  To develop a simplified approach of virtual functional assessment of coronary stenosis from routine angiographic data and test it against fractional flow reserve using a pressure wire (wire-FFR).
  
  
  RESULTS
  Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by wire-FFR (reference standard: ≤0.80). The 3D-QCA models were processed with computational fluid dynamics (CFD) to calculate the lesion-specific pressure gradient (ΔP) and construct the ΔP-flow curve, from which the virtual functional assessment index (vFAI) was derived. The discriminatory power of vFAI for ischaemia- producing lesions was high (area under the receiver operator characteristic curve [AUC]: 92% [95% CI: 86-96%]). Diagnostic accuracy, sensitivity and specificity for the optimal vFAI cut-point (≤0.82) were 88%, 90% and 86%, respectively. Virtual-FAI demonstrated superior discrimination against 3D-QCA-derived % area stenosis (AUC: 78% [95% CI: 70- 84%]; p<0.0001 compared to vFAI). There was a close correlation (r=0.78, p<0.0001) and agreement of vFAI compared to wire-FFR (mean difference: -0.0039±0.085, p=0.59).
  
  
  CONCLUSIONS
  We developed a fast and simple CFD-powered virtual haemodynamic assessment model using only routine angiography and without requiring any invasive physiology measurements/hyperaemia induction. Virtual-FAI showed a high diagnostic performance and incremental value to QCA for predicting wire-FFR; this "less invasive" approach could have important implications for patient management and cost.
authors.affiliation: Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece.
authors.forename: Michail I
authors.initials: MI
authors.lastname: Papafaklis
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Lampros S
authors.initials: LS
authors.lastname: Lakkas
authors.forename: Shimpei
authors.initials: S
authors.lastname: Nakatani
authors.forename: Christos V
authors.initials: CV
authors.lastname: Bourantas
authors.forename: Jurgen
authors.initials: J
authors.lastname: Ligthart
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Onuma
authors.forename: Mauro
authors.initials: M
authors.lastname: Echavarria-Pinto
authors.forename: Georgia
authors.initials: G
authors.lastname: Tsirka
authors.forename: Anna
authors.initials: A
authors.lastname: Kotsia
authors.forename: Dimitrios N
authors.initials: DN
authors.lastname: Nikas
authors.forename: Owen
authors.initials: O
authors.lastname: Mogabgab
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: van Geuns
authors.forename: Katerina K
authors.initials: KK
authors.lastname: Naka
authors.forename: Dimitrios I
authors.initials: DI
authors.lastname: Fotiadis
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
authors.forename: Héctor M
authors.initials: HM
authors.lastname: Garcia-Garcia
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Felix
authors.initials: F
authors.lastname: Zijlstra
authors.forename: Lampros K
authors.initials: LK
authors.lastname: Michalis
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D000368:Aged; D003198:Computer Simulation; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D012189:Retrospective Studies