Introduction. During the last two decades, many authors have found that
European Systems for Cardiac Operative Risk Evaluation (additive and logistic
models) overestimate the risk in cardiac surgery. The new European model has
recently been introduced as an update to previous versions. The aim of the
study was to investigate the significance of locally derived system for
cardiac operative risk evaluation and to compare its predictive power with
the existing European systems. Material and Methods. For developing a local
risk prediction model, data from 2681 patients submitted to cardiac surgery
at the Institute of Cardiovascular Diseases Vojvodina have thoroughly been
collected. Logistic regression analysis was used to construct a local model
for prediction of outcome. The evaluation of the local model and three
European systems was performed by comparing the observed and expected
hospital mortality. Results. The difference between the predicted and
observed mortality regardless of the type of surgery was statistically
insignificant for the additive European system (p=0.073) and the local model
(p=0.134). The logistic European system overestimated the operative risk,
while the new European model underestimated mortality. In coronary surgery,
all models, except the logistic European system, performed well. In valvular
surgery, the new European model and the local model underestimated mortality
significantly, while the additive and logistic European models performed
well. In combined surgery, the new European system significantly
underestimated mortality (p=0.029), while the local model performed well
(p=0.252). Conclusion. The locally derived model shows satisfactory results,
with good calibration and discriminative power. The local model specifically
outperforms all other European systems in terms of discriminatory power in
combined surgery subset.