Transcatheter Treatment of Bicuspid Aortic Valve Stenosis: From Observational Studies to Randomized Clinical Trials.

Bicuspid aortic valve (BAV) disease is the most common congenital heart abnormality, which affects up to 2% of the population and significantly increases the lifetime risk of aortic stenosis and the need for valve replacement. While surgical aortic valve replacement (SAVR) remains the standard of care in low surgical-risk patients, transcatheter aortic valve implantation (TAVI) is increasingly used as a treatment alternative with favorable outcomes in well-selected BAV patients. To date, randomized controlled trials comparing TAVI and SAVR have excluded patients with BAV, except the UK TAVI and the more recent The NOrdic Aortic Valve IntervenTION-2 trial. Of note, in The NOrdic Aortic Valve IntervenTION-2 trial, there was a numerical imbalance in the BAV subgroup, with more events observed in the TAVI group than in the SAVR group for the composite outcome (all-cause mortality, stroke, and rehospitalization) at 1- and 3-year follow-up, although the risk estimates were imprecise due to the limited number of events. The upcoming TraNscatheter Aortic Valve Implantation versus surGical AorTic valvE replacement in patients with Bicuspid aortic valve stenosis (NAVIGATE Bicuspid) and Bicuspid aortic valve replacement: EvaLuatIon of transcathetEr VERsus Surgery (BELIEVERS) trials will directly compare TAVI and SAVR in BAV populations. These trials are designed to provide robust, adequately powered estimates of the comparative safety and effectiveness of both interventions over extended follow-up and are expected to inform future guideline recommendations in the setting of BAV anatomy. This review summarizes current data on the use of TAVI in patients with severe BAV stenosis, evaluates anatomical and procedural complexities, and outlines the design and rationale of upcoming randomized controlled trials addressing this critical knowledge gap.