Redo-TAVI with the SAPIEN 3 valve in degenerated calcified CoreValve/Evolut explants
David S. Meier, Anish Nigade, Althea Lai, Kyle Dorman, Hacina Gill, Shahnaz Javani, Mariama Akodad, David Wood, Toby Rogers, Rishi Puri, Keith B. Allen, Adnan K. Chhatriwalla, Michael J. Reardon, Gilbert H.L. Tang, Vinayak Bapat, John G. Webb, Shinichi Fukuhara, Stephanie Sellers
Abstract
BACKGROUND: Redo-transcatheter aortic valve implantation (TAVI) is the treatment of choice for failed transcatheter aortic valves. Currently, implantation of a SAPIEN 3 (S3) is indicated for redo-TAVI in degenerated CoreValve/Evolut (CV/EV) transcatheter aortic valves (TAVs) but is not well understood. AIMS: We aimed to evaluate S3 function following implantation in explanted calcified CV/EV TAVs and to assess the impact of CV/EV pathology on redo-TAVI outcomes. METHODS: Ex vivo hydrodynamic testing was performed per the International Organization for Standardization (ISO) 5840-3 standard on 4 S3 TAVs implanted at node 5 in calcified CV/EV explants. The mean gradient (MG), effective orifice area (EOA), peak velocity, regurgitant fraction (RF), geometric orifice area (GOA), leaflet overhang, leaflet pinwheeling, neoskirt height, and frame deformation were evaluated. RESULTS: CV/EV explants were calcified and stenotic. Following S3 implantation, the MG and peak velocity decreased. As per the ISO standard, all S3 implants showed adequate EOA, and 3 out of 4 had an RF within the accepted value (<20%). CV/EV leaflet overhang ranged from 25-37%. Calcified leaflets remained stationary throughout the cardiac cycle (difference <9%) and were not pinned in a manner that constrained S3 systolic flow or appeared to prevent selective frame cannulation. The downstream CV/EV GOA was larger than the upstream S3 GOA during systole. S3 frame underexpansion was seen, resulting in leaflet pinwheeling (range 13-30%). Above the neoskirt, calcium protrusion was observed in contact with the S3 leaflets. CONCLUSIONS: S3 implantation at node 5 in calcified CV/EV valves resulted in satisfactory hydrodynamic performance in most configurations tested with stable leaflet overhang throughout the cardiac cycle. The long-term implications of S3 underexpansion, leaflet pinwheeling, and calcium protrusion require future studies.