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

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Biomedical Engineering

Background:

• The feasibility of repeat transcatheter aortic valve replacement (TAVR) and subsequent coronary access after initial implantation of the Abbott Navitor valve remains unclear.
• Understanding the impact of Navitor valve implant depth is crucial for planning future interventions.

Purpose of the Study:

• To evaluate the feasibility of redo-TAVR using the Edwards Sapien 3 (S3) valve and assess coronary access after initial Navitor valve implantation.
• To determine the influence of various Navitor valve implant depths on redo-TAVR and coronary access feasibility using computed tomography (CT) simulations.

Main Methods:

• Utilized 2050 pre-TAVR CT scans to simulate initial Navitor valve implantation at 0 mm, 3 mm, and 5 mm depths.
• Assessed redo-TAVR feasibility based on valve-to-sinotubular junction and valve-to-sinus height distances (<2 mm considered unfeasible).
• Determined coronary access feasibility based on the neoskirt height of the S3 valve relative to the target implant depth.

Main Results:

• Redo-TAVR was least unfeasible (2.3%) with Navitor at 3 mm depth and S3 implanted lower (Node 2), compared to 40.5% when S3 was implanted higher (Node 3) (P < 0.0001).
• Coronary access was least challenging with Navitor at 3 mm depth and S3 implanted lower (Node 2) (P < 0.0001).
• Results were consistent across all Navitor valve sizes; commissural alignment improved redo-TAVR feasibility only at 5 mm implant depth.

Conclusions:

• CT simulations indicate that an initial Navitor implant depth of 3 mm, with subsequent S3 valve implantation lower (Node 2), offers the most favorable conditions for redo-TAVR and coronary access.
• In vivo validation is necessary to confirm the predictive accuracy of these CT simulation findings for clinical practice.