In Vivo Computed Tomography Sizing for Redo-Transcatheter Aortic Valve Replacement in Evolut Valves: Impact on Sizing, Feasibility, and Prosthesis-Patient Mismatch.

Background: SAPIEN3 (S3) is a ubiquitous redo-transcatheter aortic valve (TAV) replacement alternative for degenerated Evolut valves, but S3 sizing for S3-in-Evolut remains unclear. We sought to compare the impact of in vivo computed tomography (CT)-sizing on redo-TAV feasibility for S3-in-Evolut with traditional bench-sizing.

Methods: CT scans of 290 patients treated using Evolut R/PRO/PRO+ between July 2015 and December 2021 were analyzed. S3-in-Evolut was simulated using S3 outflow/neoskirt plane (NSP) at node-6, -5, and -4. CT-sizing for S3 was determined by averaging 4 areas of the Evolut stent frame at NSP level and 3 nodes below. Redo-TAV was deemed feasible if the NSP was below the coronaries, or the narrowest valve (virtual S3)-to-aorta distance was >4 mm. Risk of prosthesis-patient mismatch was estimated using predicted indexed-effective orifice area.

Results: Compared with bench-sizing, CT-sizing yielded smaller S3 size in 82% at node-6, 81% at node-5, and 84% at node-4. Factors associated with CT-sizing less than bench-sizing were larger index Evolut size, underexpansion of index Evolut, and shallower implant depth (all P<0.05). CT-sizing increased redo-TAV feasibility by +8% at node-6, +10% at node-5, and +4% at node-4. Redo-TAV feasibility increased with annulus size, sinotubular junction dimensions, coronary heights, index Evolut size, deeper Evolut implant depth, and lower NSP levels (all P<0.05). CT-sizing had a slightly higher estimated risk of severe prosthesis-patient mismatch (9% at node-6, 7% at node-5, and 6% at node-4), which could be mitigated by changing the NSP.

Conclusions: CT-sizing for S3-in-Evolut is associated with higher feasibility of redo-TAV compared with bench-sizing, potentially reducing the risk of excessive oversizing and S3 underexpansion. Further validation using real-world clinical data is necessary.