Accuracy of aortic annulus measurements by three-dimensional transesophageal echocardiography and predictive value for thoracic aorta aneurysm in patients with aortic regurgitation

BACKGROUND: Accurate assessment of the aortic annulus (AA) dimension and judgment of thoracic aorta aneurysm is crucial for patients with aortic regurgitation (AR) before surgery. The aim of this study was to evaluate the accuracy and reproducibility of three-dimensional transesophageal echocardiography (3D-TEE) methods for AA measurement and explore the predictive value of the AA dimensions obtained by 3D-TEE for high-risk thoracic aorta aneurysms using the gold standard of multi-slice computed tomography (MSCT). METHODS: 3D-TEE was performed on 111 patients with pure moderate-to-severe AR, and MSCT examination was conducted simultaneously. AA dimensions were obtained using reconstruction software for these two imaging techniques. Thoracic aortic diameters at standard anatomic landmarks were also measured by MSCT. All patients were divided into two groups depending on the presence of high-risk thoracic aorta aneurysms. RESULTS: Compared to MSCT, 3D-TEE overestimated all AA parameters. However, no statistically significant differences were found in the average bias between methods (minimum diameter: 26.07±3.57 vs. 25.88±3.68 mm, P=0.52; maximum diameter: 32.30±2.68 vs. 31.78±4.06 mm, P=0.11; area: 669.76±155.19 vs. 660.05±168.28 mm(2), P=0.44; perimeter: 93.52±10.42 vs. 92.26±11.71 mm, P=0.12). 3D-TEE demonstrated good correlations with MSCT measurement for AA minimum diameter, maximum diameter, area, and perimeter (r=0.63, 0.64, 0.74, 0.69, P<0.05 for all). According to the multivariate logistic regression analysis, the AA minimum diameter obtained by 3D-TEE was the best predictor for the presence of high-risk thoracic aorta aneurysms. The sensitivity and specificity for prediction were 84.6% and 63.9%, respectively, for an AA minimum diameter ≥25.74 mm (AUC: 0.759, 95% CI: 0.668–0.850). CONCLUSIONS: AA measurements obtained by the 3D-TEE method are feasible and reliable for patients with pure AR. The AA minimum diameter measured by 3D-TEE can effectively predict the presence of high-risk thoracic aorta aneurysms.