Can estimated glomerular filtration rate improve the EuroSCORE?

Several studies have shown that the glomerular filtration rate is a strong predictor of mortality following cardiac surgery. This study was designed to identify the estimated glomerular filtration rate using the MDRD-4 equation as an independent predictive variable of mortality and to determine whether the inclusion of this variable could improve the discriminating power of the EuroSCORE. Data from 2014 consecutive patients who underwent cardiac surgery over a 3-year period were analysed. Mean glomerular filtration rate was 68.4+/-22.7 ml/min per 1.73 m(2); 704 patients (35%) showed a rate <or=60 ml/min/1.73 m(2). An estimated glomerular filtration rate <or=60 ml/min/1.73 m(2) was found to be an independent predictor of mortality adjusted for age, sex and EuroSCORE (P<0.001, OR 2.4, 95% CI 1.6-3.4). The discriminating power of the EuroSCORE improved when this variable was included: area under the ROC curve for EuroSCORE plus estimated glomerular filtration rate was 0.77 (0.73-0.81) compared to 0.75 (0.71-0.80) for the additive EuroSCORE (z=2.55, P<0.05) and 0.75 (0.71-0.80) for the logistic EuroSCORE (z=2.45, P<0.05). The estimated glomerular filtration rate using the MDRD-4 equation is an independent predictive factor of perioperative mortality in cardiac surgery. The inclusion of this variable could improve the discriminatory capacity of the EuroSCORE.