The American Society of Thoracic Surgery Score versus EuroSCORE I and EuroSCORE II in Israeli Patients Undergoing Cardiac Surgery.

Background: Recently, Israel established the first national-level adult cardiac surgery database, which was linked to the Society of Thoracic Surgeons (STS).
Objectives: To validate and compare the STS predicted risk of mortality (PROM) to logistic EuroSCORE I (LESI) and EuroSCORE II (ESII) in Israeli patients undergoing cardiac surgery.
Methods: We retrospectively studied 1279 consecutive patients who underwent cardiac surgeries with a calculable PROM. Data were prospectively entered into our database and used to calculate PROM, LESI, and ESII. Scores were normalized and correlated using linear regression and Pearson's test. To examine model calibration, we plotted the total observed versus expected mortality for each score and across five risk-score subgroups. Model discrimination was assessed by measuring the area under the receiver operating curves.
Results: The observed 30-day operative mortality was 1.95%. The median (IQ1; IQ3) PROM, LESI, and the ESII scores were 1.45% (0.69; 3.22), 4.54% (2.28; 9.27), and 1.88% (1.18; 3.54), respectively, with observed over expected ratios of 0.63 (95% confidence interval [95%CI] 0.42-0.93), 0.59 (95%CI 0.40-0.87), and 0.24 (95%CI 0.17-0.36), respectively, (STS vs. ESII P = 0.36, STS vs. LESI P = 0.0001). There was good correlation among all scores. All models overestimated mortality. Model discrimination was high and similar for all three scores. Model calibration of the STS, PROM, and ESII were more accurate than the LESI, particularly in higher risk subgroups.
Conclusions: All scores overestimated mortality. In Israeli patients, the STS, PROM, and ESII risk-scores were more reliable metrics than LESI, particularly in higher risk patients.