Impact of Methodologic Differences in Three-Dimensional Echocardiographic Measurements of the Aortic Annulus Compared with Computed Tomographic Angiography Before Transcatheter Aortic Valve Replacement

Abstract

Three-dimensional (3D) echocardiographic (3DE) imaging is an alternative to multi-detector row computed tomography (MDCT) for aortic annular measurement before transcatheter aortic valve replacement (TAVR). A commonly used direct planimetry from a reconstructed short-axis view has not been compared with semiautomated 3DE methods. Typically accepted optimal cutoffs for percent prosthesis-area oversizing of the balloon-expandable SAPIEN or SAPIEN XT valve to native annular size are approximately 5% to 15%. The aim of this study was to compare semiautomated and direct planimetric 3DE methods for aortic annular sizing with a gold standard of MDCT to determine predictive value for paravalvular regurgitation (PVR) and balloon postdilatation. In this retrospective analysis, aortic annular cross-sectional area was measured from pre-TAVR imaging using (1) MDCT (CT_Area), (2) a 3D transesophageal echocardiographic (TEE) semiautomated method(3DE_Area_SA), and (3) a 3D TEE direct planimetric method (3DE_Area_Direct). Annular area percent oversizing was calculated. PVR after TAVR was assessed from intraoperative TEE imaging. Need for balloon postdilatation was recorded. One hundred patients who underwent TAVR with either the SAPIEN or SAPIEN XT balloon-expandable prosthesis were analyzed. Twenty-three patients hadmild or greater PVR after TAVR. CT_Area was 442±79mm2, 3DE_Area_SA was 435±81mm2, and 3DE_Area_Direct was 429±82mm2. Both 3DE_Area_SA and 3DE_Area_Direct underestimated MDCT (P<.05). All methods were highly correlative (R=0.88-0.93, P<.0001). Percent oversizing obtained by the three methods significantly predictedmild or greater PVR and need for balloon postdilatation by receiver operating characteristic analysis, with optimal cutoffs for CT_Area (9%-10%) and 3DE_Area_SA (14%) within the recommended ranges for the studied transcatheter valves and for 3DE_Area_Direct higher than the recommended range (18%-19%). Inter- and intraobserver reproducibility were lowest for 3DE_Area_Direct. Caution must be used when using 3D TEE direct planimetry of the aortic annulus, as optimal percent oversizing ranges approach the level associated with root injury, and measurements are less reproducible. Therefore, semiautomated 3DE planimetry is preferred to 3DE direct planimetry for aortic annulus sizing.