Patients with severe aortic stenosis (sAS) treated with transcatheter aortic valve implantation (TAVI) (increasingly younger \& lower risk pts) are experiencing SVD of the index THV and thus developing an indication for a redo-TAVI procedure. The evidence on redo-TAVI (where a transcatheter heart valve \[THV\] is implanted into another THV) is limited, with initial data showing acceptable safety as well efficacy in highly selected and limited populations. Aim is to evaluate short- and long-term data on patients undergoing transcatheter redo-TAVI procedures with THVs for failure of a previously implanted THV and to determine VARC-3 defined efficacy and safety at 30 days and functional outcome at 1 year, 3 years and 5 years.