The study will evaluate the efficacy and safety of transcatheter aortic valve implantation (TAVI) using the Hydra transcatheter aortic heart valve (THV) series, in patients with severe aortic stenosis up to 1-year after the procedure. This will include an evaluation of the preservation of coronary access post implant by attempting to selectively engage both the right and left coronary arteries through standardised angiographic views. The study will also examine the utility of 72 hours of post discharge remote ambulatory continuous electrocardiogram (ECG) monitoring using the novel Checkpoint Cardio System where it is clinically appropriate.