Abstract 20775: Value of Multislice Computed Tomography to Evaluate Aortic Annulus Diameter and Shape in Patients Referred for Transcathter Aortic Valve Implantation: A Comparison With TTE and TTE and Potential Impact on the Choice of the Prosthesis Diameter
The present study evaluates the aortic annulus diameter and shape in patients with aortic stenosis referred for transcatheter aortic valve implantation (TAVI) with the Edwards SAPIEN valve using multislice computed tomography (MSCT), transesophageal echocardiography (TEE) and transthoracal echocardiography (TTE). The aortic annulus diameter evaluated by the different modalities was further compared with the diameter of the prosthesis used in patients without aortic regurgitation.
Method: Preoperative annulus diameter was measured in 47 patients using MSCT, TEE and TTE. Of these, 38 patients referred for TAVI and received whether a 23 mm or 26 mm prosthesis with no aortic regurgitation were used as controls. In all patients the maximal and minimal diameter of the aortic annulus was measured by MSCT and the hinge-hinge length was measured by TEE and TTE. Calcification of the aortic valves was classified as 1=minimal, 2= moderate and 3=severe calcification. Computer software 3mensio (Medical imaging BV) was used for 3D CT analyzes.
Results: The mean maximal diameter of the aortic annulus measured by MSCT was 28,6 ± 3,1 and the mean minimal diameter was 25,8 ± 3,0. Mean difference between the two diameters was 5,5 ± 2,8. This indicates an ellipsoid shape of the annulus diameter. This shape tended to become circular in patients with severe calcifications with a smaller difference between the 2 diameters (4,8 ± 2,8 vs 7,8 ± 2,1, p =0.01, see table). The mean diameter was larger by MSCT compared to TTE or TEE (p=0.005, see table). The mean difference between prosthesis-size and aortic annulus diameter was smaller when measured by MSCT (1,6 ± 1,1 mm) compared to the diameter measured by TEE or TTE (p= 0.01, see Table).
Conclusion: MSCT identified the ellipsoid shape of the aortic annulus diameter. Aortic annulus diameter was underestimated by TTE and TEE compared with diameter measured by MSCT. The latter approach seems the best method to select the right prosthesis-size in TAVI procedures.
- © 2010 by American Heart Association, Inc.