Understanding trends in transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) utilization is essential for predicting valve-in-valve (ViV) TAVR usage, a viable option for failed bioprosthetic valves that presents a promising avenue for lifetime management of aortic stenosis. This study aimed to predict and compare the future annual ViV volume in the United States and Japan based on past and current TAVR/SAVR utilization under some underlying assumptions. We developed a MATLAB-based Monte Carlo model engine to simulate the lifespan of bioprosthetic TAVR and SAVR valves. The valves are simulated for each individual TAVR/SAVR procedure from 1998 to 2035, accounting for over 4.4 million AVRs in the United States and 800,000 AVRs in Japan. The model allocates ages of the index procedure, valve durability, patient survival postprocedure, and accounts for redo open-heart procedures (in the U.S. model). The model outputs for total annual ViV volume for the United States and Japan show strong alignment with the 2023 TVT (Transcatheter Valve Therapy) and 2024 J-TVT (Japanese Transcatheter Valve Therapy) registry data, respectively. Both the U.S. and Japan ViV trends are made up of 2 parts-TAVR-in-SAVR dominates initially, after which TAVR-in-TAVR rises and dominates, with TAVR-in-SAVR flattening out after 2028. Total ViV is projected to reach approximately 42,000 (95% CI: 41,888-42,112) U.S. procedures (∼15% of U.S. TAVR) and 4,972 (95% CI: 4,935-5,009) Japanese procedures (∼8% of Japanese TAVR) in 2035. Future ViV procedures are predicted to surge in the United States and Japan, with TAVR-in-TAVR dominating both markets in 2035.
Ohno et al. (Fri,) studied this question.