Abstract 18662: Aortic Valve Orientation Angle is Associated With Aortic Morphology and Dissection Risk

Abstract

Introduction: Asymmetric aortic root enlargement may lead to unequal thinning of the aortic wall, differential shear stresses and dissection. We sought the association of aortic root morphology with aortoventricular angle (AVAng), LVOT-root angle (RootAng), root-aorta angle (AortAng) [Fig 1] and outcomes. Methods: Demographic, morphometric and epidemiological parameters were gathered in 100 patients with aortic disease over last 6 years and 50 age and sex matched controls undergoing aortic CT. Two observers measured AVAng, RootAng, AortAng between the proximal aorta, aortic annulus and LV outflow tract [Figure 1] and orthogonal diameters along the thoracic aorta, noting the type of arch and other pathologies. The root axis was taken by joining the midpoints of aortic annulus and sinotubular junction, and asymmetry index (AI) [Fig 1] was calculated as the ratio of the maximal distance between axis and right wall, and axis to left wall in coronal view. There were 22 aortic dissections in the study group, and follow up was 32.3 months. Results: AortAng was different between TAV and BAV, but AI and AVAng were similar. AortAng [P= 0.008], AI [P= 0.004] and AVAng [p=0.013] had the strongest correlation with aortic dilatation [>40 mm], and were different in the dissection group (Table). The AI correlated well with root dilatation while AortAng and AVAng correlated with ascending aortic dilatation. TAV had a diffuse pattern of aortic dilatation as compared to BAV. Conclusions: AVAng and RootAng correlate with aortic dilatation patterns, and also aortic dissection. The AVAng and AortAng may explain the differential shear stresses seen along the 2 curvatures in aortic pathologies.