Procedural Volume and Outcomes of Transfemoral Transcatheter Aortic Valve Replacement: From a Japanese Nationwide Registry.

The impact of procedural volume on transcatheter aortic valve replacement (TAVR) outcomes in Japan remains uncertain. Japan has carefully introduced TAVR after the establishment of techniques in Western countries and therefore may not exhibit volume-outcome relations after TAVR. Data on transfemoral TAVR was collected from the Japan Transcatheter Valve Therapy (J-TVT) registry between 2018 and 2020. Hospitals were categorized into quartiles (lowest, lower, high, and highest) based on annual TAVR volume. The primary analysis compared 30-day mortality among different TAVR volume hospitals. A multivariable adjustment analysis was performed to calculate the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) of 30-day all-cause mortality with highest-volume hospital as the reference. A total of 2,741 transfemoral TAVR cases from 172 hospitals were included in the analysis. Median hospital TAVR volume was 38 (interquartile range 27 to 60) per year. Unadjusted 30-day mortality was 0.46%, 0.69%, 1.17%, and 1.18% from the lowest to the highest quartile of hospitals, respectively. There was no significant difference in 30-day mortality rates for lowest-volume hospitals (aOR 0.51, 95% CI 0.24 to 1.05, p = 0.07), low-volume hospitals (aOR 0.76, 95% CI 0.46 to 1.26, p = 0.29), or high-volume hospitals (aOR 1.11, 95% CI 0.74 to 1.67, p = 0.60). An analysis from the contemporary national registry in Japan did not find an obvious inverse relation between annual hospital volume and 30-day mortality. Our results suggest that TAVR has now reached a level of procedural maturity, with standardized outcomes observed across hospitals regardless of their annual procedural volume.