Is it possible to improve the accuracy of EuroSCORE?

We derived a new risk-scoring method by modifying some of the risk factors included in the EuroSCORE algorithm.

This study includes 3613 patients who underwent cardiac surgery at the Vaasa Central Hospital, Finland. The EuroSCORE variables, along with modified age classes (< 60 years, 60-69.9 years, 70-79.9 years and > or = 80 years), eGFR-based chronic kidney disease classes (classes 1-2, class 3 and classes 4-5) and the number of cardiac procedures, were entered into the regression analysis.

An additive risk score was calculated according to the results of logistic regression by adding the risk of the following variables: patients' age classes (0, 2, 4 and 6 points), female (2 points), pulmonary disease (3 points), extracardiac arteriopathy (2 points), neurological dysfunction (4 points), redo surgery (3 points), critical preoperative status (8 points), left ventricular ejection fraction (> 50%: 0; 30-50%: 2 and < 30%: 3 points), thoracic aortic surgery (8 points), postinfarct septal rupture (9 points), chronic kidney disease classes (0, 3 and 6 points), number of procedures (1: 0; 2: 2 and 3 or more: 7 points). The modified score had a better area under the receiver operating characteristic curve (additive: 0.867; logistic: 0.873) than the EuroSCORE (additive: 0.835; logistic: 0.840) in predicting 30-day postoperative mortality. The modified score, but not EuroSCORE, correctly estimated the 30-day postoperative mortality.

EuroSCORE still performs well in identifying high-risk patients, but significantly overestimates the immediate postoperative mortality. This study shows that the score's accuracy and clinical relevance can be significantly improved by modifying a few of its variables. This institutionally derived risk-scoring method represents a modification and simplification of the EuroSCORE and, likely, it would provide a more realistic estimation of the mortality risk after adult cardiac surgery.