Agreement of Transthoracic and Three‐Dimensional Transesophageal Echocardiography With Surgical Aortic Annular Sizing: Insights From a Retrospective Study

Background Reliable preoperative assessment of the aortic annulus is essential for aortic valve replacement and transcatheter aortic valve implantation (TAVI). Transthoracic echocardiography (TTE) and three‐dimensional transesophageal echocardiography (3D TEE) are commonly used noninvasive tools for annular sizing; however, their agreement with intraoperative surgical sizing remains uncertain, particularly because surgical sizing reflects a postexcisional functional annular dimension rather than a direct anatomical gold standard. Objective To evaluate and compare the agreement of TTE and 3D TEE with direct surgical sizing of the aortic annulus. Methods This retrospective study included 106 patients who underwent aortic valve replacement between January 2019 and December 2023. The mean patient age was 57.2 ± 9.8 years (median 57, IQR 46–66), and 68 patients (64.2%) were male. The surgical annulus diameter had a median of 23 mm (IQR 22–25 mm). TTE and 3D TEE yielded lower annular diameters with medians of 22 mm (IQR 20–23 mm) and 22 mm (IQR 21–24 mm), respectively. Compared with surgical sizing, the median differences were −2 mm (IQR −4 to 0 mm, p < 0.001) for TTE and −1 mm (IQR −3 to 1 mm, p = 0.010) for 3D TEE. Bland–Altman analysis demonstrated wide limits of agreement for both modalities (TTE: −6 to +2 mm; 3D TEE: −6 to +4 mm). The correlation between TTE and 3D TEE was strong ( r = 0.790, p < 0.001), whereas correlations between each echocardiographic modality and surgical sizing were very weak and statistically nonsignificant (TTE: r = 0.084; 3D TEE: r = 0.038). Conclusion TTE and 3D TEE demonstrated limited agreement with surgical aortic annular sizing, with weak correlations and wide limits of agreement. Although 3D TEE showed smaller mean systematic bias than TTE at the group level, substantial individual‐level variability remained. Because surgical sizing is performed after leaflet excision and annular debridement and reflects functional rather than purely anatomical sizing, these findings should be interpreted as agreement with surgical sizing rather than validation against a true anatomical gold standard.