Comparison of echocardiographic results of CoreValve versus Edwards Sapien valves in patients with bicuspid aortic valve

Although the first transcatheter aortic valve implantation (TAVI) was performed in a bicuspid aortic valve (BAV) stenosis, treatment of BAV with TAVI has traditionally been regarded as a relative contraindication [1,2]. Asymmetry of the valve orifice and annulus with heavily calcified leaflets and raphe could impair the expansion of transcatheter aortic valves, eventually leading to paravalvular leak and poor hemodynamic function. Nevertheless, limited number of case reports demonstrated the feasibility of TAVI in BAV stenosis [3–5]. We read with a great interest the manuscript by Watanabe et al. [6] titled “Comparison of Multislice Computed Tomography Findings Between Bicuspid and Tricuspid Aortic Valves Before and After Transcatheter Aortic Valve Implantation” published on January 9, 2015 in the Catheterization and Cardiovascular Interventions. The authors reported that the postprocedural mean transaortic gradient was significantly higher after CoreValve implantation in BAV compared to tricuspid aortic valves (TAV) while this situation was not observed with the Edwards valve. They proposed that CoreValve bioprosthesis may not fully expand in patients with heavily calcified BAV leading to a residual pressure gradient. In order to make such a conclusion in favor of balloon-expandable valve we think that a head-to-head comparison of CoreValve and Edwards valves in BAV group for post-procedural mean transaortic gradients should have been analyzed, however the authors did not mention such an analysis in their study. We suggest this gap should absolutely be filled with a revision. If there is significant difference between the bioprosthetic valves in BAV group, this result will be more interesting since in a recently published study with more participants any significant difference was not found between bioprosthetic valves in BAV [7]. Furthermore, it is plausible to think that compliance of self-expandable bioprosthesis will be greater to an oval shaped annulus because of the unique properties of nitinol in the CoreValve and the oval shape at the inflow portion of bioprosthesis is not expected to affect the valvular functions since the level of the leaflets is supra-annular. Finally, if calcification of aortic valve actually limits the self-expandable valve to expand then it will also be expected to occur in the case of calcified TAV which was not observed in any study before. In contrast, the mean post-procedural transaortic gradients were found to be lower with the effective orifice tending to be greater in CoreValve than Edwards valve [8].