Aortic stenosis (AS) is a degenerative process affecting the aortic valve that leads to sclerosis of the valve and limits its opening during cardiac contractions. The prognosis is poorly, with survival rates of only 15-50% at 5 years. AS has a major impact on quality of life, with severely limiting symptoms (dyspnea, chest pain,…) often leading to repeated hospitalizations. It is the most common valvular disease in Europe and North America, and its prevalence is increasing as the population ages. In Europe, 17% of the population is aged 65 or over; in France, this proportion will reach 30% by 2030, corresponding to 16 million people. The incidence of aortic valve sclerosis (early stage AS) is around 25% at age 65, rising to 48% after age 75. The prevalence of aortic valve disease is likely to continue to rise, given the expected evolution of the age pyramid. There is no medical treatment able to slow down the degenerative process of the valve, and the only treatment is aortic valve replacement when the AS becomes constricted and the patient is eligible for an intervention. Aortic valve replacement has historically been performed surgically, with open-chest surgery to remove the damaged valve and replace it with a mechanical or biological valve prosthesis. Now Transcatheter Aortic Valve Implantation (TAVI) has replaced this procedure. This involves inserting a bioprosthesis crimped into a stent via an endovascular route, i.e. without opening the thorax. Deployment of the stent crushes the native valve, leaving the functional bioprosthesis in place. Initially developed for patients contraindicated to surgery, TAVI is now offered as a first-line treatment for patients aged 75 and over. Inexistent before 2010, the number of TAVIs equalled the number of surgeries by 2015, and TAVIs currently account for ¾ of aortic valve procedures (unpublished data).