C16 - Comparison of Two-dimensional Transesophageal Echocardiographic Quantification of Mitral Valve Annular Area with Three-dimensional Planimetric Imaging

Abstract: Background- With new interventional procedures aimed at treating degenerative valve disease, the need to stratify patients into surgical categories is necessary. Some methods for determining regurgitant fraction require accurate quantification of mitral annular area (MAA). This retrospective study evaluated MAA with standard two-dimensional (2D) transesophageal (TEE) measurements compared with three-dimensional (3D) planimetry.

Hypothesis- 2D orthogonal views will most closely approximate MAA compared with the reference standard 3D planimetry.

Animals- Thirty-two dogs of variable breed and size

Methods- All TEE studies were performed as part of catheter-based interventions including congenital disease and transcatheter edge-to-edge mitral valve repair (TEER). Studies were reviewed using 3D planimetry and traditional apical 2D views: 2-chamber (2CH), 4-chamber (4CH), commissural (CC), and anterior-posterior (AP). Data were assessed for normality using a Shapiro-Wilk test. Continuous variables comparing 2D with 3D planimetry were assessed using a Friedmean test with Dunn’s multiple comparisons, Spearman rank correlation, and Bland-Altman plots. A P < 0.05 was considered significant.

Results- Two-dimensional apical 2CH and 4CH MAA and orthogonal 4Ch/2CH and CC/AP ellipse MAA were not significantly different than planimetry. There was significant correlation between planimetry and 4CH (r = 0.95, P < 0.001), 2CH (r = 0.92, P < 0.01), 4CH/2CH (r = 0.97, P < 0.0001), and CC/AP (r = 0.99, P < 0.0001). Among these variables CC/AP had the smallest bias (0.09  0.37) and closest limits of agreement (-0.63 to 0.81) with planimetry.

Conclusion and Clinical Importance- Two-dimensional CC/AP derived MAA is an acceptable alternative to 3D planimetry in dogs.