title: Evaluation of Aortic Blood Flow and Wall Shear Stress in Aortic Stenosis and Its Association With Left Ventricular Remodeling.
abstract: BACKGROUND
  Aortic stenosis (AS) leads to variable stress for the left ventricle (LV) and consequently a broad range of LV remodeling. The aim of this study was to describe blood flow patterns in the ascending aorta of patients with AS and determine their association with remodeling.
  
  
  RESULTS
  Thirty-seven patients with AS (14 mild, 8 moderate, 15 severe; age, 63±13 years) and 37 healthy controls (age, 60±10 years) underwent 4-dimensional-flow magnetic resonance imaging. Helical and vortical flow formations and flow eccentricity were assessed in the ascending aorta. Normalized flow displacement from the vessel center and peak systolic wall shear stress in the ascending aorta were quantified. LV remodeling was assessed based on LV mass index and the ratio of LV mass:end-diastolic volume (relative wall mass). Marked helical and vortical flow formation and eccentricity were more prevalent in patients with AS than in healthy subjects, and patients with AS exhibited an asymmetrical and elevated distribution of peak systolic wall shear stress. In AS, aortic orifice area was strongly negatively associated with vortical flow formation (P=0.0274), eccentricity (P=0.0070), and flow displacement (P=0.0021). Bicuspid aortic valve was associated with more intense helical (P=0.0098) and vortical flow formation (P=0.0536), higher flow displacement (P=0.11), and higher peak systolic wall shear stress (P=0.0926). LV mass index and relative wall mass were significantly associated with aortic orifice area (P=0.0611, P=0.0058) and flow displacement (P=0.0058, P=0.0283).
  
  
  CONCLUSIONS
  In this pilot study, AS leads to abnormal blood flow pattern and peak systolic wall shear stress in the ascending aorta. In addition to aortic orifice area, normalized flow displacement was significantly associated with LV remodeling.
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.). florian.von-knobelsdorff@charite.de.
authors.forename: Florian
authors.initials: F
authors.lastname: von Knobelsdorff-Brenkenhoff
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Achudhan
authors.initials: A
authors.lastname: Karunaharamoorthy
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Ralf Felix
authors.initials: RF
authors.lastname: Trauzeddel
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Barker
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Edyta
authors.initials: E
authors.lastname: Blaszczyk
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.affiliation: From the Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine and HELIOS Klinikum Berlin Buch, Department of Cardiology and Nephrology, Berlin, Germany (F.v.K.-B., A.K., R.F.T., E.B., J.S.-M.); Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL (A.J.B., M.M.); and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (M.M.).
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
mesh_terms: D000368:Aged; D001011:Aorta / Q000503:physiopathology*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology*; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D010865:Pilot Projects; D011446:Prospective Studies; D012039:Regional Blood Flow; D013314:Stress, Mechanical; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
keywords: aorta; aortic valve stenosis; heart valve diseases; heart ventricles; magnetic resonance imaging