Feasibility of redo-TAVI in self-expanding Evolut valves: a CT analysis from the Evolut Low Risk Trial substudy

Background: Transcatheter aortic valve implantation in an existing transcatheter valve (redo-TAVI) pins the index valve leaflets in the open position (neoskirt), which can cause coronary flow compromise and limit access. Whether anatomy may preclude redo-TAVI in self-expanding Evolut valves is unknown. Aims: We aimed to evaluate the anatomical feasibility of redo-TAVI by simulating implantation of a bal-loon-expandable SAPIEN 3 (S3) within an Evolut or an Evolut within an Evolut. Methods: A total of 204 post-TAVI computed tomography (CT) scans from the Evolut Low Risk CT sub -study were analysed. Five redo-TAVI positions were evaluated: S3-in-Evolut inflow-to-inflow, S3 outflow at Evolut nodes 4, 5, and 6, and Evolut-in-Evolut inflow-to-inflow. Univariable modelling identified pre-TAVI clinical characteristics, CT anatomical parameters, and procedural variables associated with coronary flow compromise using the neoskirt height and post-TAVI aortic root dimensions. Results: The risk of coronary flow compromise was lowest when the S3 outflow was at Evolut node 4 (20%) and highest when at Evolut node 6 (75%). The highest likelihood of preserving coronary accessi-bility occurred with the S3 outflow at Evolut node 4. Female sex and higher body mass index were associ-ated with a higher risk of coronary flow compromise, as were a smaller annulus diameter, lower sinus of Valsalva height and width, shorter coronary height, smaller sinotubular junction diameter, and shallower Evolut implant depth. Conclusions: The feasibility of redo-TAVI after Evolut failure is multifactorial and relates to the native annular anatomy, as well as the implantation depth of the index and second bioprostheses. Placement of an S3 at a lower Evolut position may reduce the risk of coronary flow compromise while preserving coronary access. ClinicalTrials.gov: NCT02701283.