Analysis of United States and Japanese TAVR Registries Supports Feasibility of International Comparisons

March 4, 2022—The Joint Data Harmonization Initiative of the Society of Thoracic Surgeons /American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) registry and Japanese Transcatheter Valvular Therapy (J-TVT) registry conducted a study comparing postapproval national clinical registry data on transcatheter aortic valve replacement (TAVR) between the United States and Japan on patient characteristics, periprocedural outcomes, and the variability of outcomes as a part of the Harmonization-by-Doing partnership program between the two countries.

Investigators extracted patient-level data from the STS/ACC TVT and the J-TVT registries to analyze practice patterns and outcomes of TAVR between 2013 and 2019 in the United States and Japan. Data entry for these registries was mandated by the federal regulators, and the majority of variable definitions were harmonized to allow direct data comparison.

The findings were published by Tsuyoshi Kaneko, MD, et al online in Journal of the American Heart Association (JAHA).

As summarized in the JAHA abstract, the investigators analyzed a total of 244,722 TAVR procedure from 646 institutions in the United States and 26,673 TAVR procedures from 171 institutions in Japan. Median volume per site was 65 (interquartile range, 45–97) in the United States and 28 (interquartile range, 19-41) in Japan.

The investigators reported the following in the United States registry versus the Japan registry:

• Patient characteristics in the United States registry versus the Japan registry included: mean age (80.1 ± 8.7 years vs 84.4 ± 5.2 years; P < .001); sex (45.9% women vs 68.1% women; P < .001); and median Society of Thoracic Surgeons Predicted Risk of Mortality (5.27% vs 6.2%; P < .001).
• Outcomes in the United States registry versus the Japan registry included: unadjusted 30-day mortality (3.2% vs 1.3%; P < .001); composite death, stroke, and bleeding events (22.5% vs 17.5%; P < .001); and conversion to open surgery (0.56% vs 0.94%; P < .001).

In the JAHA abstract, the investigators concluded, "This collaborative analysis between the United States and Japan demonstrated the feasibility of international comparison using the national registries coded under mutual variable definitions. Both countries obtained excellent outcomes, although the Japanese had lower 30-day mortality and major morbidity. Harmonization-by-Doing is one of the key steps needed to build global-level learning to improve patient outcomes."