Thoracic aorta 3D hemodynamics in pediatric and young adult patients with bicuspid aortic valve. Issue 4 (22nd January 2015)

• Record Type: Journal Article
• Authors: Allen, Bradley D.; van Ooij, Pim; Barker, Alex J.; Carr, Maria; Gabbour, Maya; Schnell, Susanne; Jarvis, Kelly B.; Carr, James C.; Markl, Michael; Rigsby, Cynthia; Robinson, Joshua D.
• Is Part Of: Journal of magnetic resonance imaging. Volume 42:Issue 4(2015)
• Page Start: 954
• Page End: 963
• Publication Date: 2015-01-22
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24847
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24847-sec-0001" sec-type="section"> <title>Background</title> <p>To evaluate the 3D hemodynamics in the thoracic aorta of pediatric and young adult bicuspid aortic valve (BAV) patients.</p> </sec> <sec id="jmri24847-sec-0002" sec-type="section"> <title>Methods</title> <p>4D flow MRI was performed in 30 pediatric and young adult BAV patients (age: 13.9 ± 4.4 (range: [3.4, 20.7]) years old, M:F = 17:13) as part of this Institutional Review Board‐approved study. Nomogram‐based aortic root Z‐scores were calculated to assess aortic dilatation and degree of aortic stenosis (AS) severity was assessed on MRI. Data analysis included calculation of time‐averaged systolic 3D wall shear stress (WSS<sub>sys</sub>) along the entire aorta wall, and regional quantification of maximum and mean WSS<sub>sys</sub> and peak systolic velocity (vel<sub>sys</sub>) in the ascending aorta (AAo), arch, and descending aorta (DAo). The 4D flow MRI AAo vel<sub>sys</sub> was also compared with echocardiography peak velocity measurements.</p> </sec> <sec id="jmri24847-sec-0003" sec-type="section"> <title>Results</title> <p>There was a positive correlation with both mean and max AAo WSS<sub>sys</sub> and peak AAo vel<sub>sys</sub> (mean: r = 0.84, <italic>P</italic> < 0.001, max: r = 0.94, <italic>P</italic> < 0.001) and AS (mean: r<sub>S</sub> = 0.43, <italic>P</italic> = 0.02, max: r<sub>S</sub> = 0.70, <italic>P</italic> < 0.001). AAo peak velocity was significantly higher when measured with echo compared with 4D flow MRI (2.1 ± 0.98 m/s versus 1.27 ± 0.49 m/s, <italic>P</italic> < 0.001).</p> </sec> <sec id="jmri24847-sec-0004" sec-type="section"> <title>Conclusion</title> <p>In pediatric and young adult patients with BAV, AS and peak ascending aorta velocity are associated with increased AAo WSS, while aortic dilation, age, and body surface area do not significantly impact AAo hemodynamics. Prospective studies are required to establish the role of WSS as a risk‐stratification tool in these patients. J. Magn. Reson. Imaging 2015;42:954–963.</p> </sec> </abstract>