Two-Dimensional Transesophageal Echocardiography Assessment of the Major Aortic Annulus Diameter in Patients Undergoing Transcatheter Aortic Valve Replacement

Abstract

Background: Multidetector computed tomography (MDCT) is the gold standard in annulus sizing before transcatheter aortic valve replacement (TAVR). However, MDCT has limited applicability in specific subgroups of patients, such as those with atrial fibrillation and chronic kidney disease. Two-dimensional transesophageal echocardiography (2DTEE) has traditionally been limited to the long-axis measurement of the anteroposterior diameter of the aortic annulus. We describe a new 2DTEE approach for the measurement of the major diameter of the aortic annulus.

Methods: Seventy-six patients with symptomatic severe aortic valve stenosis and high surgical risk underwent MDCT and 2DTEE before TAVR. A modified five-chamber view was used to measure the major aortic annulus diameter. This was obtained starting from a mid-esophageal four chamber and retracting the TEE probe up until the left ventricular outflow tract and the left and noncoronary aortic cusps were visualized: major aortic annulus diameter was measured as the distance between their insertion points in systole.

Results: Major aortic annulus diameters measured at 2DTEE showed good correlation with MDCT diameter (r = 0.79; P < 0.001) and perimeter (r = 0.87; P < 0.0001). Using factsheet-derived sizing criteria, 2DTEE alone would have allowed accurate sizing in 75% of patients, with 21% of oversizing predominantly with smaller annuli.

Conclusions: We describe a new method for 2DTEE measurement of the major aortic annulus diameter; this approach is simple, correlates with MDCT, and allows adequate TAVR sizing in most patients. These findings may help in the assessment of patients with contraindications to or inadequate MDCT images.

Keywords: Aortic annulus; echocardiography; transcatheter aortic valve replacement; transesophageal echocardiography.

Figure 1

Modified transesophageal echocardiography five-chamber view for the measurement of major aortic annular diameter. (a) From a standard mid-esophageal 0° four-chamber view (left), the probe is pulled up until the base of the left and noncoronary cusps is visualized (right), and the distance between the insertion points of the two cusps is measured at end-systole. (b) Three-dimensional transesophageal echocardiography reconstructions showing the anatomical premises of the approach; green panel (upper left) demonstrates the modified five-chamber view described above; red panel (upper right) represents an orthogonal-plane reconstruction showing correct alignment with the true major annulus diameter; a grid on the far right serves as geometrical model of the anatomy of the aortic annulus, valve, and root

Figure 2

Major diameters measured by multidetector computed tomography (left column) and two-dimensional transesophageal echocardiograph (right column); the three cases refer to patients with small (21 mm), intermediate (26 mm), and large (31 mm) CoreValve size selection

Figure 3

Correlation between two-dimensional transesophageal echocardiograph major diameter and multidetector computed tomography major diameter (Panel A) and final prosthesis size (Panel B)

Figure 4

Bland–Altman chart depicting agreement between multidetector computed tomography and two-dimensional transesophageal echocardiograph major annular diameters; solid line defines mean bias, dashed lines define upper and lower LOA (±1.96 standard deviation)

Figure 5

Prosthesis size prediction by two-dimensional transesophageal echocardiograph stratified by actual final prosthesis size