In BAV patients, 2D TTE underestimates aortic annulus area by 32% and aortic valve area by 29% due to annulus orientation orthogonal to the ultrasound beam.
Does 2D TTE underestimate aortic annulus area compared to contrast-enhanced CT in patients with bicuspid aortic valve?
In patients with bicuspid aortic valves, 2D TTE significantly underestimates aortic annulus and valve areas compared to CT because the maximum annulus diameter is orthogonal to the ultrasound beam.
Absolute Event Rate: 0% vs 0%
Abstract Background In the setting of bicuspid aortic valve (BAV), the assessment of aortic annulus morphology remains poorly defined. Purpose We aim to evaluate the morphology and orientation of the maximum diameter of the aortic annulus in BAV patients using contrast-enhanced computed tomography. Methods We included 159 BAV patients (male: 75%, mean age 55 ±19): 70 with severe aortic stenosis and 89 with ascending aorta enlargement without significant valvulopathy. All patients underwent transthoracic echocardiography (TTE) and contrast-enhanced computed tomography (CT). Results The annulus was asymmetric (eccentricity index: 0.23±0.09) and the Sievers class was not a determinant of annular eccentricity (type 0: 0.26±0.09 vs. type 1: 0.23±0.08, p=0.068). The aortic annulus maximum diameter orientation was evaluated using CT sagittal plane as a reference. This orientation was not dependent on BAV phenotype: horizontal opening: 109.6±28.6° vs vertical opening 111.2 ±28.8°, p=0.87. This is in contrast with the aortic root maximum diameter which is dependent on the BAV phenotype: horizontal or vertical opening: 71.3±35.5° vs. 122.9±35.5°, p0.0001. (Figure) As a result, diameter obtained in the parasternal long-axis incidence is always the short axis of the ellipse. Using this measure to calculate the annulus area therefore leads to underestimation of annulus area if eccentricity index is not taken into account. The mean difference of the annulus area using TTE vs CT is 142.2mm² i.e., 32% and 0.62cm² i.e., 29% for the aortic valve area. Conclusion orientation of the maximum aortic annulus diameter is orthogonal to the TTE ultrasound beam in BAV patients, irrespective of BAV type. Our results suggest that TTE can lead to an underestimation of annulus area and, consequently, aortic valve area.
Cacoub et al. (Sat,) reported a other. In BAV patients, 2D TTE underestimates aortic annulus area by 32% and aortic valve area by 29% due to annulus orientation orthogonal to the ultrasound beam.