Author + information
- Matheus Simonato1,
- Ali Azadani2,
- Michael Reardon3,
- Gabriel Aldea4,
- Georg Nickenig5,
- Ran Kornowski6 and
- Danny Dvir4
Transcatheter heart valve implantation in failed aortic bioprostheses (valve-in-valve,ViV) is an increasingly used therapeutic option for high-risk patients. However, high post-procedural gradients are a significant limitation of aortic ViV. Our Objective was to evaluate Medtronic CoreValve® Evolut® R ViV hemodynamics in relation to the degree of device oversizing and depth of implantation.
23mm and 26mm Evolut R devices were implanted within 21, 23, and 25mm Hancock® II bioprostheses. Small and gradual changes in implantation depth were attempted. Hemodynamic testing was performed in a pulse duplicator under ISO-5840 standard.
A total of 47 bench-testing experiments were performed. The mean gradient of the 26mm Evolut R in 23mm and 25mm Hancock II was lower than 23mm Evolut R (p<0.001). However, mean gradient of 26mm Evolut R in 21mm Hancock II bioprostheses R (ranging from 21.30±0.23 to 24.30±0.22mm-Hg) was worse than 23mm Evolut R (ranging from 15.94±0.18 to 20.35±0.16mm-Hg, p<0.001). Furthermore, our results suggest that supra-annular implantation of 23mm and 26mm Evolut R devices within the bioprostheses can lead to lower gradient and improved leaflet coaptation. Regardless of implantation depth, superior transvalvular gradient is expected with 26mm Evolut R than 23mm Evolut R in a non-stenotic Hancock II with a true internal diameter > 17.5mm.
The current comprehensive bench testing assessment demonstrates the importance of both transcatheter heart valve size and device position for the attainment of optimal hemodynamics during ViV procedures. Additional in vitro testing may be required to develop hemodynamics-based guidelines for device sizing in ViV procedure in degenerated surgical bioprostheses.