Geometric coronary constraints and anatomical feasibility of redo TAVR in Asian patients with Evolut valves: A CT-based simulation study

Redo transcatheter aortic valve replacement (TAVR) when implanting a second transcatheter valve within a tall-frame self-expanding valve can be challenging because of unfavorable coronary-related anatomy. However, computed tomography (CT)-based data in Asian patients with smaller aortic root dimensions remain limited.This study aimed to evaluate the CT-based geometric coronary constraints by simulating implantation of a balloon-expandable SAPIEN 3 (S3) within a previously implanted self-expanding Evolut valve in Asian patients. Consecutive patients who underwent TAVR using Evolut at a single center between May 2021 and May 2023 and had post-procedural CT were analyzed. Virtual S3-in-Evolut implantation was simulated at three depths (node 4: low; node 5: intermediate; node 6: high). Geometric coronary constraint was assessed based on the relationship between the neo-skirt plane and coronary ostia and the valve-to-aorta distance. Among 113 patients, the distribution of geometric coronary constraint differed by simulated S3 implantation depth. With high S3 implantation (node 6), severe, intermediate, and low constraint were observed in 63.7%, 23.9%, and 12.4% of patients, respectively; with intermediate implantation (node 5), in 31.0%, 29.2%, and 39.8%; and with low implantation (node 4), in 3.5%, 16.8%, and 79.6%. In multivariable analysis, smaller sino-tubular junction diameter was independently associated with severe geometric coronary constraint.Geometric coronary constraints that may affect coronary access after redo TAVR with S3-in-Evolut configurations depend on the implantation depth of both the index Evolut and the simulated S3. However, the hemodynamic significance and clinical impact of these geometric findings require validation through flow studies.