Impact of type of procedure and surgeon on EuroSCORE operative risk validation

OBJECTIVE: EuroSCORE has been used in cardiac surgery operative risk assessment, despite important variables were not included. The objective of this study was to validate EuroSCORE on mortality prediction in a Brazilian cardiovascular surgery center, defining the influence of type of procedure and surgical team. METHODS: Between January 2006 and June 2011, 2320 consecutive adult patients were studied. According to additive EuroSCORE, patients were divided into low risk (score<2), medium risk (3 - 5), high risk (6 - 11) and very high risk (>12). The relation between observed mortality (O) and expected mortality (E) according to logistic EuroSCORE was calculated for each of the groups, types of procedures and surgeons with > 150 operations, and analyzed by logistic regression. RESULTS: EuroSCORE correlated to the observed mortality (O/E=0.94; P<0.0001; area under the curve 0.78). However, it overestimated the mortality in very high risk patients (O/E=0.74; P=0.001). EuroSCORE tended to overestimate isolated myocardial revascularization mortality (O/E=0.81; P=0.0001) and valve surgery mortality (O/E=0.89; P=0.007) and it tended to underestimate combined procedures mortality (O/E=1.09; P<0.0001). EuroSCORE overestimated surgeon A mortality (O/E=0.46; P<0.0001) and underestimated surgeon B mortality (O/E=1.3; P<0.0001), in every risk category. CONCLUSION: In the present population, EuroSCORE overestimates mortality in very high risk patients, being influenced by type of procedure and surgical team. The most appropriate surgical team may minimize risks imposed by preoperative profiles.