Comparison of Semiautomated and Hybrid Three-Dimensional Transesophageal Echocardiography With Multidetector Computed Tomography for Aortic Annular Sizing in Transcatheter Aortic Valve Replacement Candidates.

Accurate aortic annular sizing is essential for transcatheter aortic valve replacement. While multidetector computed tomography (MDCT) remains the reference standard, three-dimensional transesophageal echocardiography (3D TEE) is frequently used when computed tomography is contraindicated; however, semiautomated 3D TEE is associated with systematic annular underestimation that may lead to prosthesis undersizing. In a prospective single-center cohort of 45 candidates for transcatheter aortic valve replacement undergoing both MDCT and 3D TEE, aortic annular diameter, perimeter, and area were compared using semiautomated 3D TEE, a hybrid approach incorporating manual Flexi-Slice multiplanar reconstruction, and MDCT. Annular underestimation was quantified relative to MDCT, and clinical relevance was assessed by agreement in hypothetical transcatheter heart valve sizing using manufacturer-recommended perimeter-based algorithms. Semiautomated analysis significantly underestimated annular diameter, perimeter, and area compared with multidetector computed tomography (all p <0.001) and resulted in 31% discordance in hypothetical valve sizing. The hybrid approach demonstrated significantly lower annular underestimation and improved agreement with MDCT, reducing valve sizing discordance to 13% and increasing overall agreement from 69% to 87%. Coronary height measurements showed a weak correlation between hybrid 3D TEE and MDCT. In conclusion, although all 3D TEE approaches underestimate aortic annular dimensions compared with MDCT, a hybrid workflow integrating manual Flexi-Slice multiplanar reconstruction significantly reduces underestimation and improves agreement in transcatheter heart valve sizing, providing a clinically valuable alternative for annular assessment when MDCT is unavailable or contraindicated.