Practice Patterns and Outcomes of Transcatheter Aortic Valve Replacement in the United States and Japan: A Report From Joint Data Harmonization Initiative of STS/ACC TVT and J-TVT

Background The practice pattern and outcome of medical devices following their regulatory approval may differ by country. The aim of this study is to compare postapproval national clinical registry data on transcatheter aortic valve replacement between the United States and Japan on patient characteristics, periprocedural outcomes, and the variability of outcomes as a part of a partnership program (Harmonization-by-Doing) between the 2 countries. Methods and Results The patient-level data were extracted from the US Society of Thoracic Surgeons /American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) and the J-TVT (Japanese Transcatheter Valvular Therapy) registry, respectively, to analyze transcatheter aortic valve replacement outcomes between 2013 and 2019. Data entry for these registries was mandated by the federal regulators, and the majority of variable definitions were harmonized to allow direct data comparison. A total of 244 722 transcatheter aortic valve replacements from 646 institutions in the United States and 26 673 transcatheter aortic valve replacements from 171 institutions in Japan were analyzed. Median volume per site was 65 (interquartile range, 45-97) in the United States and 28 (interquartile range, 19-41) in Japan. Overall, patients in J-TVT were older (United States: mean-age, 80.1±8.7 versus Japan: 84.4±5.2;