Abstract 15894: Aortic Flow Patterns and Peak Velocity Assessment Using 4D Flow MRI in Dilated Ascending Aorta With and Without Aortic Valve Stenosis and Regurgitation
Introduction: Aortic valve stenosis (AS) and regurgitation (AR) are associated with ascending aortic (AAo) dilatation. However, patients can develop AAo dilatation even with neither AS nor AR (no AS/AR).
Purpose: To characterize differences in AAo flow patterns and velocity between patients with AS, AR, and no AS/AR all with dilated AAo, and healthy controls using 4D flow MRI.
Methods: Eight patients with moderate to severe AS (72±9 years, 8 men, mid AAo diameter [MAAd]: 41±2mm), 33 patients with moderate to severe AR (62±14 years, 25 men, MAAd: 44±5 mm), 30 patients with no AS/AR (63±9 years, 22 men, MAAd: 42±4 mm) were identified via IRB-approved retrospective chart review. Twenty five healthy controls (57±10 years, 19 men, MAAd: 33±4 mm) were selected from the existing database. All subjects underwent in-vivo 4D flow MRI. AAo flow patterns were visualized with pathlines and were graded for the presence of vortex and helix flow using a 3 point scale (1, no vortex/mild helix [flow rotation < 180°]; 2, 1-2 large vortex/moderate supra-physiologic helix [flow rotation: 180° to 360°]; 3, more than 2 large vortex/prominent supra-physiologic helix [flow rotation > 360°]). Systolic peak velocities were quantified in 9 aortic segments (Fig. 3).
Results: Patients with AS, AR, and no AS/AR showed significantly elevated vortex and helix flow compared to control subjects (fig. 2; Vortex: 2.0±0.5, 2.1±0.5, and 2.0±0.4, respectively vs. 1.4±0.5, p<0.05, Helix: 2.8±0.5, 2.3±0.8, and 2.3±0.9, respectively vs. 1.7±0.7, p<0.05). Peak velocities were significantly elevated in the patients with AS from root to distal arch compared to those with AR, no AS/AR, and controls. Peak velocities were significantly increased in AR patients in the aortic root and mid AAo compared to those with no AS/AR and controls.
Conclusions: Aortic dilation is generally associated with aberrant flow patterns while the type of valve disease can further influence regional changes in aortic velocities.
Author Disclosures: K. Suwa: None. O.A. Rahman: None. E. Bollache: None. M.J. Rose: None. A.A. Rahsepar: None. H. Hayashi: None. J. Carr: None. J. Collins: None. A. Barker: None. M. Markl: None.
- © 2016 by American Heart Association, Inc.