Project 460606

Narrowing of the aortic heart valve is a frequent and serious cardiovascular disease named Aortic Stenosis: (AS) and the only available treatment is to replace the failing aortic valve by a prosthetic valve. This intervention is generally performed using open-heart surgery (surgical aortic valve replacement; SAVR) However, recently a new technique, i.e. transcatheter aortic valve implantation (TAVI) has emerged and provides a much less invasive alternative to SAVR. With this new technique, the prosthetic valve is implanted via a catheter inserted through the femoral artery without opening the chest of the patient. There are two main types of TAVI valves: balloon-expandable (BE) and self-expanding (SE) valves and it is assumed that the clinical results are equivalent with both types. However, some recent studies suggested that survival may be better with BE vs. SE valves. These important results need to be confirmed by a randomized controlled trial with large number of patients. The BEST randomized trial, which is funded by the French government, will compare BE vs. SE valves with regards to survival and quality of life at 90 days, 1 year and 5 years. In this CIHR grant application, we propose to take the unique opportunity of the BEST trial to conduct an imaging (echocardiography and computed tomography, CT) substudy to compare the 2 types of TAVI valves with regards to the risk of prosthetic valve dysfunction. The echocardiograms and CTs performed by the participating centers will be analyzed in a centralized and standardized manner in core laboratories based at the Québec Heart & Lung Institute. The BEST trial will be the first study to determine whether there is a difference between the 2 main types of TAVI valves used nowadays, for valve function, clinical, and QoL outcomes. If this study demonstrates significant differences in outcomes of TAVI between BE vs. SE valves, this could have major implications on the treatment and outcome of patients with severe AS.