Ideal Navitor Implant Depth for Redo-TAVR Feasibility and Coronary Access: A CT Simulation Study

The impact of implant depth of the Abbott Navitor intra-annular, self-expanding valve on redo-transcatheter aortic valve replacement (TAVR) feasibility is unknown.

The authors sought to determine the feasibility of redo-TAVR and coronary access with Edwards Sapien 3 (S3) valve after initial Navitor valve, based on various implant depths on computed tomography (CT) simulation.

Using 2050 pre-TAVR CTs of patients with native aortic stenosis, initial Navitor TAVR simulations were done at 3 implant depths (0 mm, 3 mm, and 5 mm), with frame expansion assumed at native annular dimensions and commissural alignment not achievable. Redo-TAVR with S3 was deemed unfeasible based on valve-to-sinotubular junction and/or valve-to-sinus height distances <2 mm, while the neoskirt height of the S3 valve based on target implant depth determined coronary access feasibility.

Redo-TAVR was deemed the least unfeasible in 2.3% of patients with initial Navitor implant depth at 3 mm and redo-S3 implanted lower at Node 2 vs 40.5% of patients with initial Navitor depth at 3 mm and redo-S3 implanted higher at Node 3 (P < 0.0001). Similarly, coronary access was the least challenging with initial Navitor depth at 3 mm and redo-S3 implanted lower at Node 2 (P < 0.0001). These results were similar across all Navitor valve sizes. Commissural alignment in Navitor improved redo-TAVR feasibility only when implanted at 5 mm.

In our CT simulation study, redo-TAVR and coronary access were predicted to be the most favorable with initial Navitor implant depth of 3 mm and redo-S3 implanted lower at Node 2. In vivo analysis will help confirm these findings.