Performance analysis of EuroSCORE II compared to the original logistic EuroSCORE and STS scores for predicting 30-day mortality after transcatheter aortic valve replacement

Abstract

The original European System for Cardiac Operative Risk Evaluation (EuroSCORE) has been recently updated as EuroSCORE II to optimize its efficacy in cardiac surgery, but its performance has been poorly evaluated for predicting 30-day mortality in patients who undergo transcatheter aortic valve replacement (TAVR). Consecutive patients (n = 250) treated with TAVR were included in this analysis. Transapical access was used in 60 patients, while 190 procedures were performed using a transfemoral approach. Calibration (risk-adjusted mortality ratio) and discrimination (C-statistic and U-statistic) were calculated for the logistic EuroSCORE, EuroSCORE II, and Society of Thoracic Surgeons (STS) scores for predicting 30-day mortality. Observed mortality was 7.6% in the overall population (6.3% and 11.7% for the transfemoral and transapical cohorts, respectively). Predicted mortality was 22.6 ± 12.8% by logistic EuroSCORE, 7.7 ± 5.8% by EuroSCORE II, and 7.3 ± 4.1% by STS score. The risk-adjusted mortality ratio was 0.34 (95% confidence interval [CI] 0.10 to 0.58) for logistic EuroSCORE, 0.99 (95% CI 0.29 to 1.69) for EuroSCORE II, and 1.05 (95% CI 0.30 to 1.79) for STS score. Moderate discrimination was observed with EuroSCORE II (C-index 0.66, 95% CI 0.52 to 0.79, p = 0.02) compared to the logistic EuroSCORE (C-index 0.63, 95% CI 0.51 to 0.76, p = 0.06) and STS (C-index 0.58, 95% CI 0.43 to 0.73, p = 0.23) score, without a significant difference among the 3 risk scores. Discrimination was slightly better in the transfemoral cohort compared to the transapical cohort with the 3 risk scores. In conclusion, EuroSCORE II and the STS score are better calibrated than the logistic EuroSCORE but have moderate discrimination for predicting 30-day mortality after TAVR.