EuroSCORE II does not show better accuracy nor predictive power in comparison to original EuroSCORE: a single-centre study

BACKGROUND: EuroSCORE is used to predict postoperative mortality in patients undergoing cardiac surgery. Its updated version was published in 2011. AIM: To assess whether EuroSCORE II (ESII) predicts more accurately postoperative mortality after cardiac surgery in comparison with additive (addES) and logistic EuroSCORE (logES). METHODS: A total of 461 patients (aged 21-88 years, 63.4% of men) who underwent cardiac surgery (December 2010 - June 2011) were included into the prospective research. For each patient ESII, addES and logES were calculated. Accuracy, calibration, and clinical performance of these models were assessed with receiver operating characteristics analyses using the area under the curve and the Hosmer-Lemeshow test. Out of this population, a group of 300 coronary artery bypass grafting (CABG) patients (aged 42-85 years, 73% of men) was selected and statistically analysed using the same methods. RESULTS: The mortality rate was 5.21%. Predicted mortality rates were as follows: addES 4.68%, logES 4.57%, and ESII 1.89%; the accuracy was: 0.589, 0.728, and 0.726, respectively. Only logES presented good predictive power (Hosmer-Lemeshow test: c2 = 12.79, p = 0.12). In the CABG patients, the postoperative mortality rate was 5.33%. Predicted mortality rates were as follows: addES 4.69%, logES 4.59%, and ESII 1.88%; the accuracy was: 0.512, 0.691, and 0.687, respectively. In the Hosmer-Lemeshow test also logES presented good predictive power (c2 = 10.72, p = 0.218). CONCLUSIONS: EuroSCORE II did not estimate mortality risk better in comparison to its previous versions, in the entire studied population or in the CABG patients. On the basis of the analysed data, it seems that the closest to the actual risk of death for the Polish population is the EuroSCORE logistic model.