title: Patient-specific computational fluid dynamics-assessment of aortic hemodynamics in a spectrum of aortic valve pathologies.
abstract: The complexity of aortic disease is not fully exposed by aortic dimensions alone, and morbidity or mortality can occur before intervention thresholds are met. Patient-specific computational fluid dynamics (CFD) were used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress (WSS), and oscillatory shear index (OSI) in the thoracic aorta.
  
  
  
  A total of 45 subjects were divided into 5 groups: volunteers, aortic regurgitation-tricuspid aortic valve (AR-TAV), aortic stenosis-tricuspid aortic valve (AS-TAV), aortic stenosis-bicuspid aortic valve right-left cusp fusion (BAV[RL]), and aortic stenosis-right-non cusp fusion (AS-BAV[RN]). Subjects underwent magnetic resonance angiography, with phase-contrast magnetic resonance imaging at the sino-tubular junction to define patient-specific inflow velocity profiles. Hemodynamic recordings were used alongside magnetic resonance imaging angiographic data to run patient-specific CFD.
  
  
  
  The BAV groups had larger mid-ascending aorta diameters (P < .05). Ascending aorta flow was more eccentric in BAV (flow asymmetry = 78.9% ± 6.5% for AS-BAV(RN), compared with 4.7% ± 2.1% for volunteers, P < .05). Helicity was greater in AS-BAV(RL) (P < .05). Mean WSS was elevated in AS groups, greatest in AS-BAV(RN) (37.1 ± 4.0 dyn/cm2, compared with 9.8 ± 5.4 for volunteers, P < .05). The greater curvature of the ascending aorta experienced highest WSS and lowest OSI in AS patients, most significant in AS-BAV(RN) (P < .05).
  
  
  
  BAV displays eccentric flow with high helicity. The presence of AS, particularly in BAV-RN, led to greater WSS and lower OSI in the greater curvature of the ascending aorta. Patient-specific CFD provides noninvasive functional assessment of the thoracic aorta, and may enable development of a personalized approach to diagnosis and management of aortic disease beyond traditional guidelines.
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom; Department of Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Pouya
authors.initials: P
authors.lastname: Youssefi
authors.affiliation: Department of Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Alberto
authors.initials: A
authors.lastname: Gomez
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom.
authors.forename: Taigang
authors.initials: T
authors.lastname: He
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom.
authors.forename: Lisa
authors.initials: L
authors.lastname: Anderson
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom.
authors.forename: Nick
authors.initials: N
authors.lastname: Bunce
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom.
authors.forename: Rajan
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Department of Biomedical Engineering, King's College London, London, United Kingdom; Departments of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, Mich.
authors.forename: C Alberto
authors.initials: CA
authors.lastname: Figueroa
authors.affiliation: Department of Cardiothoracic Surgery & Cardiology, St. George's Hospital, St. George's University of London, London, United Kingdom. Electronic address: marjan.jahangiri@stgeorges.nhs.uk.
authors.forename: Marjan
authors.initials: M
authors.lastname: Jahangiri
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001021:Aortic Valve / Q000503:physiopathology*; D001022:Aortic Valve Insufficiency / Q000503:physiopathology*; D001024:Aortic Valve Stenosis / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D019295:Computational Biology; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged
keywords: MRI; aorta; bicuspid aortic valve; wall shear stress