Comparison of Aortic Root Geometry with Bicuspid versus Tricuspid Aortic Valve: Real-Time Three-Dimensional Transesophageal Echocardiographic Study

Abstract

An understanding of aortic root anatomy in bicuspid aortic valve (BAV) has not been well established. The aims of this three-dimensional transesophageal echocardiographic study were (1) to examine whether aortic root geometry differs between BAV and tricuspid aortic valve (TAV) and (2) to analyze the dynamic motion of the aortic annulus throughout cardiac cycle. A total of 66 patients with BAV (38 with severe aortic stenosis [AS]) and 66 age-, gender-, and body surface area-matched patients with TAV (36 with severe AS) who underwent three-dimensional transesophageal echocardiography were retrospectively enrolled. The dynamic motion of the aortic annulus was also analyzed in 40 selected patients (10 with BAV with severe AS, 10 with BAV without AS, 10 with TAV with severe AS, and 10 with TAV without AS). The area of the aortic root in patients with BAV was larger than in those with TAV (aortic annulus, P < .001; sinus of Valsalva, P < .05; sinotubular junction, P < .01). There was a significant difference in circularity (4π × area/[perimeter](2)) of the sinus of Valsalva between patients with BAV and those with TAV (P < .001), although there were no differences in the shapes of the aortic annulus and the sinotubular junction between the two groups. In both patients with BAV and those with TAV, the aortic annulus in mid-systole was largest and most circular in cardiac cycle; on the other hand, in end-diastole, the aortic annulus was smallest and most elliptical (P < .001). Three-dimensional transesophageal echocardiography successfully demonstrated significant differences in the size of the aortic root and the shape of the sinus of Valsalva between patients with BAV and those with TAV.