Redo Transcatheter Aortic Valve Implantation in the Lotus Mechanically Expanded Transcatheter Heart Valve: Bench-Top Analysis, Clinical Experience, and Procedural Guidance.

BACKGROUND: Redo transcatheter aortic valve implantation (TAVI) is increasing as patients outlive their transcatheter heart valves (THVs) and present with bioprosthetic valve failure. The Lotus mechanically expanded THV has unique design characteristics, which have specific implications for Redo TAVI. METHODS: The design features of the Lotus valve and their relevance to Redo TAVI were reviewed. Bench-top analysis of Redo TAVI was performed using different contemporary THVs. Procedural and outcome data were obtained from 10 patients who had undergone Redo TAVI for Lotus bioprosthetic valve failure in 5 centers. Recommendations for performing Redo TAVI in Lotus are made, based on these findings. RESULTS: The Lotus leaflets extend from the frame inflow, with a Neoskirt of only 13 mm, hence a low risk of coronary obstruction during Redo TAVI. The Lotus frame posts prevent full apposition of the Redo prosthesis in the upper part of the frame, while implantation of the Redo THV above the Lotus inflow leads to inadequate apposition of the Lotus leaflets. Inflow-to-inflow positioning is therefore recommended for effective sealing and leaflet pinning. The Lotus locking mechanism prevents overexpansion of the frame, limiting Redo THV oversizing. Redo TAVI was favorable with SAPIEN 3, Evolut, and Navitor THVs on bench-top analysis but not with ACURATE Neo 2 due to the upper crowns and short stent preventing inflow-to-inflow deployment. Case review demonstrated satisfactory outcomes in 10 patients treated with Evolut (n=6), SAPIEN 3 (n=3), and Portico (n=1) valves, with no mortality, major morbidity, or coronary obstruction. Three patients had residual mean gradient ≥20 mm Hg, including 2 of 3 SAPIEN cases. Guidance on procedural planning, valve choice, sizing, and positioning is provided. CONCLUSIONS: Redo TAVI in Lotus requires an understanding of unique design characteristics, and adherence to key procedural recommendations, but can be safely and effectively performed with most contemporary valve types. [ABSTRACT FROM AUTHOR]