Validation of a three-dimensional trans-esophageal echocardiography analysis software to assess mitral valve annulus and predicted Neo-LVOT before trans-catheter mitral valve replacement
Authors: Mahmoud-Elsayed H , Hekal S , Emam A Y , Thabet N , Shaaban M N , Bahaa H , Elguindy A 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Trans-catheter mitral valve replacement (TMVR) procedures had emerged as an alternative solution for patients who have surgical high risk for mitral valve surgery. One of the main challenges faced during the percutaneous approach is the degree of left ventricular outflow tract (LVOT) narrowing after implanting the new percutaneous mitral prosthesis. The remaining LVOT area (NeoLVOT) can be estimated by a commercially available CT analysis software that allows the insertion of a virtual valve within the CT dataset in the native annulus and/or the degenerated bioproshesis and hence allows measurement of the NeoLVOT using the multi-planar reconstruction (MPR) mode.
Due to the radiation as well as intravenous contrast risk of the CT scans, a new 3DTEE based software was developed, using the same concept of the virtual valve implantation within the 3DTEE dataset to measure the NeoLVOT using the MPR mode. Using this 3DTEE based software avoids the risks associated with CT (radiation & contrast) and can be a reasonable alternative for patients with impaired renal function or a screening test and/or filter for all patients before proceeding to a detailed CT scan if found suitable based on the 3DTEE analysis.

Purpose
To validate the 3DTEE based software in mitral valve annulus (MA) and NeoLVOT assessment using the CT based software as a gold standard.

Methods
A retrospective observational single center study, including 49 patients (age 57± 6 years, 60% men), who had undergone Cardiac computed tomography (CT) and three-dimensional trans-esophageal echocardiography (3DTEE) within one month from each other for any clinical indication. We excluded patients who had previous mitral or aortic valve surgeries.
CT analysis was done using the commercially available software, (3mensio Structural Heart, Pie Medical Imaging, The Netherlands). 3DTEE analysis was done using the newly available software (3mensio Structural Heart 10.1–3mSH, Pie Medical Imaging, Bilthoven, Netherlands) Figure 1
Measurements done on both software were; mitral annulus (MA) antero-posterior (AP) diameter, inter-commissural (IC) diameter, annulus area (Area), annulus perimeter (Peri) and the NeoLVOT.
Excellent correlation was found between 3D-TEE and CT measurements for MA AP diameter (r= 0.96), IC diameter (r=0.92), MA area (r =0.96), MA perimeter (r= 0.94) and NeoLVOT area (r= 0.96), (all P-values &lt;0.0001). Virtual valve sizing was based on annulus measurement and was identical between CT and 3DTEE. Interobserver and intraobserver agreements were excellent for all the measurements with ICCs &gt;0.80. Figure2

Conclusions
Mitral annulus dimensions and Neo-LVOT assessment using this 3DTEE based analysis software is feasible and reliable compared to CT analysis. This can offer a good screening test or a filter for TMVR candidates and can also be a good alternative for patients who have a contraindication for CT.