Oscillatory shear stress is elevated in patients with bicuspid aortic valve and aortic regurgitation: a 4D flow cardiovascular magnetic resonance cross-sectional study

Figures

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  Figure 1. Overview of the wall shear stress-derived parameters computed in the study for a representative BAV with aortic regurgitation. WSS, wall shear stress; WSScirc, circumferential wall shear stress component; WSSaxial, axial wall shear stress component; OSI, oscillatory shear index; OSIcirc, circumferential oscillatory shear index; OSIaxial, axial oscillatory shear index.

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  Figure 2. Peak (on the left) and time averaged (on the right) WSS magnitude in the systolic and diastolic phase in the ascending aorta for the four groups: BAVs without valve disease (BAV-noVD), BAVs with aortic regurgitation (BAV-REG), BAVs with aortic stenosis (BAV-STEN), and controls with TAV (TAV), where the stars indicate a significant difference between two groups (P < 0.05/6 after applying Bonferroni correction).

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  Figure 3. Oscillatory shear index (OSI, on the left), OSI for the axial component of WSS (OSIaxial, in the centre), and OSI for the circumferential component of WSS (OSIcirc, on the right) reported in the four groups: BAVs without valve disease (BAV-noVD), BAVs with aortic regurgitation (BAV-REG), BAVs with aortic stenosis (BAV-STEN), and controls with TAV (TAV), where the stars indicate a significant difference between two groups (P < 0.05/6 after applying Bonferroni correction).

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  Figure 4. Scatter plots for OSI and maximum ascending aortic diameter (top left), peak WSS (top right), regurgitant fraction (bottom left), and stroke volume (bottom right) for the BAVs: BAVs without valve disease (BAV-noVD), BAVs with aortic regurgitation (BAV-REG), BAVs with aortic stenosis (BAV-STEN), and controls with TAV (TAV); note that one BAV-REG with ∼7% regurgitant fraction was clinically classified as having mild-to-moderate regurgitation based on visual inspection of 2D flow images.

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  Figure 5. 2D significance maps for regional comparisons for OSI, where the red areas represent regions in which BAV with regurgitation had higher OSI in that segment (P-value < 0.0052 after Bonferroni correction) compared with each other group, and grey areas are regions in which the differences were not significant between the groups: BAV-REG, BAV with regurgitation; BAV-noVD, BAV without valve disease; BAV-STEN, BAV with stenosis; TAV, TAV controls.