Observational Study Relating to the Long-term Follow-up of Patients with Severe Aortic Stenosis Evaluated for Percutaneous Aortic Valve Replacement (TAVI).

All patients with severe aortic stenosis undergoing evaluation for TAVI are routinely subjected to a series of assessments: * Pre-implantation: thoraco-abdominal CT angiography, coronary angiography, echocardiography, clinical assessment, ECG, and laboratory tests. * Post-implantation: echocardiography, laboratory tests, ECG, assessment of any procedural complications, and a cardiology follow-up visit. This is an observational study, with the aim to monitor over time the population of patients who have undergone TAVI, identifying pre- and post-implant conditions that may negatively impact patient outcomes (both clinical factors and those directly related to the prosthetic implant). Through a 10-year follow-up, the study seeks to determine the incidence of prosthetic failure, as well as the incidence of prosthesis-related complications and major clinical endpoints.