Background: One of the most utilized systems for risk stratification in cardiac surgery is the EuroSCORE. It considers some risk factors that should influence the surgical risk. The aim of this study was to evaluate if our results, related to isolated coronary artery bypass surgery, are well predictable by this system and which are the parameters statistically significant for hospital mortality.
Methods: From January 1, 2002 to April 30, 2004, 724 patients underwent isolated myocardial revascularization. All risk factors considered for the EuroSCORE system evaluation and the EuroSCORE value itself were analyzed to assess their significance to predict surgical risk. Univariate statistical analysis was performed with the Student's t-test for quantitative variables and the chi2 in contingency tables for categorical variables. Logistic regression was used for multivariate analysis.
Results: Cumulative operative mortality was 3.7% (27 patients). The EuroSCORE value, age, critical preoperative state, emergency and low ejection fraction were all statistically significant risk factors for hospital mortality. Multivariate analysis excluded only the critical preoperative state. The analysis of contingency tables showed that the surgical risk was statistically significant above the age of 75 years. The same analysis revealed that the mortality rate was statistically different in the three groups and it showed that the system could over-estimate mortality at lower EuroSCOREs and under-estimate mortality at higher EuroSCOREs.
Conclusions: This study confirms the value of the EuroSCORE for risk stratification in this group of patients. The most important parameters considered for its calculation confirmed their predictive value. This model allows a reliable quality control of our surgical practice.