Bicuspid Aortic Valve Disease: From Pathophysiology to Treatment

Abstract

The Bicuspid Aortic Valve (BAV) is the most common congenital anomaly in adults, with a global incidence of 1.3%. Despite being well documented, BAV presents significant clinical challenges due to its phenotypic heterogeneity, diverse clinical manifestations, and variable outcomes. Pathophysiologically, BAV differs from tricuspid valves in calcification patterns and hemodynamic effects, leading to increased shear stress and aortic root dilatation, while it is influenced by genetic and hemodynamic factors. This is why therapeutically, BAV presents challenges for both surgical and transcatheter interventions, with surgical approaches being traditionally preferred, especially when aortopathy is present. However, transcatheter aortic valve implantation (TAVI) has emerged as a viable option, with studies showing comparable outcomes to surgery in selected patients, while advancements in TAVI and a better understanding of BAV's genetic and pathophysiological nuances are expanding treatment options. The choice between mechanical and bioprosthetic valves also presents considerations, particularly regarding long-term durability and the need for anticoagulation. Future research should focus on long-term registries and genetic studies to refine therapeutic strategies and improve patient outcomes. This review aims to evaluate current approaches in the surgical and interventional management of BAV, focusing on its anatomy, pathogenesis, pathophysiology, and therapeutic strategies.

Keywords: aortic dilatation; aortic valve disease; bicuspid aortic valve; bicuspid aortic valve registry; congenital heart disease; future directions; hemodynamic effects; pathophysiology; surgical aortic valve replacement (SAVR); transcatheter aortic valve replacement (TAVR).

Figure 1

Expert consensus on classification of BAV.

Figure 2

BAV classification in the TAVI era [7]. Images are derived from Computed Tomography scans. Blue lines at the first two images and pink line at the third image represent the vertical axis. Green lines at the first two images and light blue line at the third image represent the horizontal axis. The burgundy colored lines at the last two images were used to indicate the different dimensions during measurements.

Figure 3

Schematic representation of the varying aortic disease phenotypes in BAV. The differing motifs of dilatation that can occur with BAV are compared to the normal aorta (top left). Although the most common distended segment is the tubular ascending aorta (A), the whole ascending aorta can be affected, including the sinuses of Valsalva and the tubular aorta with elimination of the sinotubular junction (B). A subgroup of patients can present with dilatation in the sinuses of Valsalva (C). This motif is correlated with type 1 BAV and male sex [4,13,14].

Figure 4

Echo of aortic dilatation in a 14-year-old patient with BAV. Evaluation of the aortic arch, including that the transaortic pressure gradient in the descending aorta should be necessary in all athletes and especially BAV athletes.

Figure 5

Female 93-year-old patient with severe BAV stenosis who underwent TAVI. Case from the Cath lab from “Hippokration” General Hospital Athens. Images from MDCT during preoperative planning demonstrating: (A) anatomy of the BAV and its degree of severity, (B) double oblique projection with CT reconstruction for the evaluation of the aortic annulus and ascending aorta, (C) 3D reconstruction of the aortic root and ascending aorta, (D) 3D reconstruction of the aortic root ascending aorta, aortic arch, descending aorta, and iliac arteries. The three color dots at the figure represent the 3D points for the visualization of the annular base.