title: Influence of beta-blocker therapy on aortic blood flow in patients with bicuspid aortic valve.
abstract: In patients with bicuspid aortic valve (BAV), beta-blockers (BB) are assumed to slow ascending aorta (AAo) dilation by reducing wall shear stress (WSS) on the aneurysmal segment. The aim of this study was to assess differences in AAo peak velocity and WSS in BAV patients with and without BB therapy. BAV patients receiving BB (BB+, n = 30, age: 47 ± 11 years) or not on BB (BB-, n = 30, age: 46 ± 13 years) and healthy controls (n = 15, age: 43 ± 11 years) underwent 4D flow MRI for the assessment of in vivo aortic 3D blood flow. Peak systolic velocities and 3D WSS were calculated at the anterior and posterior walls of the AAo. Both patient groups had higher maximum and mean WSS relative to the control group (p = 0.001 to p = 0.04). WSS was not reduced in the BB+ group compared to BB- patients in the anterior AAo (maximum: 1.49 ± 0.47 vs. 1.38 ± 0.49 N/m(2), p = 0.99, mean: 0.76 ± 0.2 vs. 0.74 ± 0.18 N/m(2), p = 1.00) or posterior AAo (maximum: 1.45 ± 0.42 vs. 1.39 ± 0.58 N/m(2), p = 1.00; mean: 0.65 ± 0.16 vs. 0.63 ± 0.16 N/m(2), p = 1.00). AAo peak velocity was elevated in patients compared to controls (p < 0.01) but similar for BB+ and BB- groups (p = 0.42). Linear models identified significant relationships between aortic stenosis severity and increased maximum WSS (β = 0.186, p = 0.007) and between diameter at the sinus of Valsalva and reduced mean WSS (β = -0.151, p = 0.045). Peak velocity and systolic WSS were similar for BAV patients irrespective of BB therapy. Further prospective studies are needed to investigate the impact of dosage and duration of BB therapy on aortic hemodynamics and development of aortopathy.
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Allen
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA. mmarkl@northwestern.edu.|Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA. mmarkl@northwestern.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Barker
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: Pim
authors.initials: P
authors.lastname: van Ooij
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Carr
authors.affiliation: Division of Cardiothoracic Surgery, Northwestern University, Chicago, IL, USA.
authors.forename: S Chris
authors.initials: SC
authors.lastname: Malaisrie
authors.affiliation: Division of Cardiothoracic Surgery, Northwestern University, Chicago, IL, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: McCarthy
authors.affiliation: Department of Medicine - Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Bonow
authors.affiliation: Department of Medicine - Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Preeti
authors.initials: P
authors.lastname: Kansal
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D001021:Aortic Valve / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D000082882:Bicuspid Aortic Valve Disease; D001783:Blood Flow Velocity; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: 4D flow MRI; Aortic dilatation; Beta blocker; Bicuspid aortic valve
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