Validation of the European system for cardiac operative risk evaluation II in a large Taiwan cardiac surgical centre.

Background: The European System for Cardiac Operative Risk Evaluation (EuroSCORE II) is a well-established scoring system for predicting mortality in cardiac surgery. This system was derived predominantly from a European patient cohort; however, no validation of this system has been conducted in Taiwan. We sought to assess the performance of EuroSCORE II at a tertiary centre.

Methods: The 2161 adult patients receiving cardiac surgery between 2017 and 2020 in our institution were included.

Results: Overall, the in-hospital mortality rate was 7.89%. The performance of EuroSCORE II was assessed using the area under the receiver operator curve (AUC) for discrimination and the Hosmer-Lemeshow (H-L) test for calibration. Data were analysed for type of surgery, risk stratification, and status of the operation. EuroSCORE II had good discriminative power (AUC=0.854, 95% Confidence Interval (CI): 0.822-0.885) and good calibration (χ2=5.19, p=0.82) for all types of surgery except ventricular assist devices (AUC=0.618, 95% CI: 0.497-0.738). EuroSCORE II also showed good calibration for most types of surgery except coronary artery bypass surgery (CABG) combined procedure (P=0.033), heart transplantation (HT) (P=0.017), and urgent operation (P=0.041). EuroSCORE II significantly underestimated the risk for CABG combined procedure and urgent operations, and overestimated the risk for HT.

Conclusions: EuroSCORE II had satisfactory discrimination and calibration power to predict surgical mortality in Taiwan. However, the model is poorly calibrated for CABG combined procedure, HT, urgent operation, and, likely, lower- and higher-risk patients.