title: Haemodynamic assessment of human coronary arteries is affected by degree of freedom of artery movement.
abstract: Abnormal haemodynamic parameters are associated with atheroma plaque progression and instability in coronary arteries. Flow recirculation, shear stress and pressure gradient are understood to be important pathogenic mediators in coronary disease. The effect of freedom of coronary artery movement on these parameters is still unknown. Fluid-structure interaction (FSI) simulations were carried out in 25 coronary artery models derived from authentic human coronaries in order to investigate the effect of degree of freedom of movement of the coronary arteries on flow recirculation, wall shear stress (WSS) and wall pressure gradient (WPG). Each FSI model had distinctive supports placed upon it. The quantitative and qualitative differences in flow recirculation, maximum wall shear stress (MWSS), areas of low wall shear stress (ALWSS) and maximum wall pressure gradient (MWPG) for each model were determined. The results showed that greater freedom of movement was associated with lower MWSS, smaller ALWSS, smaller flow recirculation zones and lower MWPG. With increasing percentage diameter stenosis (%DS), the effect of degree of freedom on flow recirculation and WSS diminished. Freedom of movement is an important variable to be considered for computational modelling of human coronary arteries, especially in the setting of mild to moderate stenosis.
  
  
  BACKGROUND
  3D: Three-dimensional; 3DR: Three-dimensional Reconstruction; 3D-QCA: Three-dimensional quantitative coronary angiography; ALWSS: Areas of low wall shear stress; CAD: Coronary artery disease; CFD: Computational fluid dynamics; %DS: Diameter stenosis percentage; EPCS: End point of counter-rotating streamlines; FSI: Fluid-structure interaction; IVUS: Intravascular ultrasound; LAD: Left anterior descending; MWSS: Maximum wall shear stress; SST: Shear stress transport; TAWSS: Time-averaged wall shear stress; WSS: wall shear stress; WPG: Wall pressure gradient; MWPG: Maximum wall pressure gradient; FFR: Fractional flow reserve; iFR: Instantaneous wave-free ratio.
authors.affiliation: a Faculty of Medicine and Health Sciences , Macquarie University , Sydney , Australia.|b ANZAC Research Institute , The University of Sydney , Sydney , Australia.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Javadzadegan
authors.affiliation: a Faculty of Medicine and Health Sciences , Macquarie University , Sydney , Australia.|b ANZAC Research Institute , The University of Sydney , Sydney , Australia.|c Department of Cardiology, Concord Hospital , The University of Sydney , Sydney , Australia.
authors.forename: Andy S C
authors.initials: AS
authors.lastname: Yong
authors.affiliation: c Department of Cardiology, Concord Hospital , The University of Sydney , Sydney , Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Chang
authors.affiliation: d Department of Cardiology , Royal Prince Alfred Hospital , Sydney , Australia.
authors.forename: Martin K C
authors.initials: MK
authors.lastname: Ng
authors.affiliation: e School of Management , Macquarie University , Sydney , Australia.
authors.forename: Masud
authors.initials: M
authors.lastname: Behnia
authors.affiliation: b ANZAC Research Institute , The University of Sydney , Sydney , Australia.|c Department of Cardiology, Concord Hospital , The University of Sydney , Sydney , Australia.
authors.forename: Leonard
authors.initials: L
authors.lastname: Kritharides
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003198:Computer Simulation; D003324:Coronary Artery Disease / Q000503:physiopathology; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006321:Heart / Q000502:physiology; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009068:Movement; D016011:Normal Distribution; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D011312:Pressure; D033081:Shear Strength; D013314:Stress, Mechanical; D014463:Ultrasonography
keywords: Fluid–structure interaction; coronary artery; degree of freedom of movement; flow recirculation; wall pressure gradient; wall shear stress