Transcatheter Aortic Valve Implantation in Bicuspid Aortic Valve Pathology: Current Evidence and Technical Challenges.

Transcatheter aortic valve implantation (TAVI) is an established therapy for severe symptomatic aortic valve stenosis (AS) in patients at high and intermediate risk for surgical aortic valve replacement (SAVR). Current evidence also suggests at least non-inferiority of TAVI in low-risk patients compared to SAVR. However, there are special subsets of patients and anatomical circumstances in which TAVI is traditionally considered a suboptimal treatment strategy due to procedure inherent increased risks (e.g., rupture of cardiac chambers in patients with severe calcifications of the left ventricular outflow tract, valve migration in very large aortic annuli). One of these special subsets is bicuspid AS. Bicuspid aortic valve disease is the most common congenital heart defect and most frequent reason for AS in patients <70 years of age. Bicuspid aortic valve pathology is characterized by special anatomical complexities like asymmetrical cusp proportion and calcium distribution, a more pronounced annular ellipticity compared to tricuspid aortic valves and concomitant dilation of the thoracic aorta. These factors have led physicians to traditionally indicate TAVI more reluctantly in those patients in the past. In this article, current evidence for TAVI for bicuspid AS is discussed and technical challenges are highlighted.