Limitations of EuroSCORE for Measurement of Risk-Stratified Mortality in Aortic Arch Surgery Using Selective Cerebral Perfusion: Is Advanced Age No Longer a Risk?

Background The European system for cardiac operative risk evaluation (EuroSCORE) is a risk stratification tool for perioperative mortality of cardiothoracic surgery that was developed in Europe and validated in North America in more than 500,000 patients. The operative mortality of aortic arch surgery has been improved by various novel operative techniques and adjuncts, whereas the number of such procedures for elderly patients has recently been increasing. The aim of this study was to examine the usefulness of the EuroSCORE, and our modification of it regarding age, in predicting mortality after aortic arch repair performed with selective cerebral perfusion. Methods We reviewed 358 consecutive patients with a mean age of 69 ± 10 years undergoing aortic arch repair with selective cerebral perfusion between January 1993 and February 2004. Observed in-hospital mortality was compared with predicted mortality as determined by both additive and logistic EuroSCOREs. We also evaluated a version of the EuroSCORE modified for age, which was obtained by subtracting the contribution of age from the original EuroSCORE. Score validities were assessed by calculating the areas under receiver operating characteristic curves. Results Overall hospital mortality was 6.2% compared with 7.7% (additive EuroSCORE) and 11.8% (logistic EuroSCORE). Area under the receiver operating characteristic curve was 0.58 for the additive EuroSCORE and 0.58 for the logistic EuroSCORE as well. The overall age-unrelated EuroSCOREs were 5.1% (additive) and 5.2% (logistic), respectively, and areas under the receiver operating characteristic curve were 0.70 for additive and 0.69 for logistic. Conclusions The original additive and logistic EuroSCOREs overpredicted mortality in this patient group, whereas the age-unrelated EuroSCORE was better in predicting mortality.