External Validation of Mortality Prediction Models in Japanese Transcatheter Aortic Valve Replacement Registry

Ryo Shibata1, Tomotsugu Seki1,2, Yuki Takeda1

  • 1Department of Cardiology, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.

Abstract

Insights

The Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PRoM) and Netherlands Heart Registration (NHR) models showed the best short-term performance in Japanese transcatheter aortic valve replacement (TAVR) patients. The Optimized CathEter vAlvular iNtervention-TAVI (OCEAN-TAVI) model demonstrated the best long-term performance.

Area of Science:

  • Cardiovascular Medicine
  • Medical Statistics
  • Health Services Research

Background:

  • Mortality prediction models (MPMs) are vital for assessing transcatheter aortic valve replacement (TAVR) risk.
  • The external validity of existing MPMs in Japanese TAVR populations is not well-established.
  • This study aimed to validate short-term and long-term MPMs in Japanese TAVR patients.

Purpose of the Study:

  • To evaluate the performance of established short-term (30-day) and long-term (1-year) mortality prediction models in a Japanese cohort undergoing TAVR.
  • To assess the discrimination and calibration of these models using data from a prospective multicentre registry.
  • To identify the most accurate models for risk stratification in this specific patient population.

Main Methods:

  • Analysis of 1756 patients for short-term and 1235 patients for long-term mortality from the KPUM TAVI registry (2016-2023).
  • Validation of five short-term MPMs (STS-PRoM, FRANCE-2, OBSERVANT, ACC-TAVI, NHR) and three long-term MPMs (OCEAN-TAVI, Osaka University, TARI).
  • Performance assessment using Area Under the Receiver Operating Characteristic Curve (AU-ROC) for discrimination and calibration metrics; intercept recalibration applied to short-term models.

Main Results:

  • Short-term mortality was 1.4% (25/1756), and long-term mortality was 14.5% (179/1235).
  • For short-term mortality, NHR (AU-ROC: 0.82) and STS-PRoM (0.78) exhibited the highest discrimination; all models initially overestimated risk, improving post-recalibration.
  • For long-term mortality, OCEAN-TAVI and Osaka University models showed the highest discrimination (AU-ROC: 0.75), with OCEAN-TAVI demonstrating superior calibration.

Conclusions:

  • The STS-PRoM and NHR models demonstrated superior short-term predictive performance in Japanese TAVR patients following recalibration.
  • The OCEAN-TAVI model exhibited the best overall long-term performance and calibration in this cohort.
  • Future research should investigate machine learning-based models to enhance the accuracy and clinical utility of TAVR risk prediction.