Spanish Prospective Registry of Hydra THV for Transcatheter Aortic Valve Implantation

Inclusion Criteria: Participants who meet ALL of the following conditions will be included: * Age ≥ 18 years and; * Severe aortic stenosis with indication for aortic valve replacement in which a Hydra THV device is implanted according to the instructions for use; and * Signed informed consent. Exclusion Criteria: Patients who do NOT meet ANY of the following conditions will be included: * Express refusal by the participant to participate in the study. * Aortic stenosis patients who are not candidates for Hydra THV device implantation or in whom implantation of this device is performed for an indication other than aortic stenosis (especially pure native aortic valve insufficiency). Patients in whom the Hydra THV device is implanted to treat patients with degenerated aortic bioprostheses may be included in the study. * Participants in randomised clinical trials who have not reached the research endpoint. * Pregnant and/or breastfeeding women.