Background .– Precise measurement of the aortic annulus diameter (AAD) is critical for successful implantation of transcatheter aortic valve (TAVI) but the most accurate method is still debated. We sought to compare immediate TAVI results according to whether transesophageal echocardiography (TEE) or multislice computed tomography (MSCT) measurement were finally used for the choice of the prosthesis size.

Methods .– We enrolled consecutive patients with severe aortic stenosis who undergone a TAVI with either the Edwards Sapien or the Medtronic CoreValve at our institution and had both TEE/MSCT measurement of the AAD. AAD was measured in long-axis view using TEE and at the level of the virtual basal ring (mean of long and short axis) using MSCT. Agreement was defined as the same choice of the prosthesis size according to manufacturers’ recommendations using both TEE and MSCT. The primary endpoint was a composite of paravalvular regurgitation, second balloon inflation or second prosthesis implantation, and prosthesis migration. Complications were assessed according to VARC definitions.

Results .– We enrolled 177 patients (81.5 ± 9 years, 56.5% male, Euroscore 22%, ejection fraction < 50%: 37%, mean aortic valve area 0.76 ± 0.20 cm ² and mean gradient 51 ± 19 mmHg). Overall, mean AD was significantly larger using MSCT than using TEE (23.3 ± 1.9 vs. 24.6 ± 2.1 mm, P < 0.0001). An agreement between TEE and MSCT as regard to prosthesis size was achieved in 117 patients. Among the 60 patients in whom a disagreement between TEE and MSCT measurements was observed, prosthesis size was chosen according to TEE measurements in 55 and according to MSCT measurements in 5. Although not achieving statistical significance, the composite criteria was more frequent in the disagreement TEE-based group (23%) compared to the agreement group (11%) and the disagreement MSCT based group (0%) ( P = 0.09). Paravalvular regurgitations were not significantly increased in the disagreement TEE-based group. There was no significant difference between the two groups concerning annulus rupture, but they were more frequent in the disagreement MSCT-based group.

Conclusion .– Our study suggests that when CT and TEE disagree, a TEE-based strategy seems to be associated with a higher rate of paravalvular regurgitation whereas a CT-based strategy may be associated with a higher rate of annulus rupture. Our results deserve further continuation and support the need for randomized study comparing CT/TEE based strategy.