0057 : Preoperative Growth Differentiation Factor 15 (GDF15) as a novel biomarker of acute kidney injury after cardiac bypass surgery

Abstract

Previously, we demonstrated that preoperative plasma GDF15 levels significantly improved the prognostic value of the EuroSCORE for mortality after cardiac surgery. Despite the strong correlation between GDF15 and renal function, no data are available regarding the potential interest of preoperative GDF15 levels to improve the prediction of acute kidney injury (AKI) after coronary artery bypass grafting (CABG). 134 patients operated on for CABG of whom 50 underwent offpump surgery at our university hospital were included in this prospective, observational study. Exclusion criteria were age <18 years or >80 years, previous atrial fibrillation/flutter, previous severe renal failure (estimated glomerular filtration rate (eGFR) <30ml/min), previous cardiac surgery, and emergency surgery. AKI was defined according to KDIGO criteria. GDF15 levels in plasma were measured before induction and 12 hours after surgery. 42 patients developed postoperative AKI which had significantly higher preoperative plasma GDF15 levels (OR=2.851; 95%CI=1.32-6.13, p=0.008), higher preoperative serum creatinine levels (OR=1.025; 95%CI=1.003-1.05; p=0.026), and most often underwent cardiopulmonary bypass (CPB) surgery (OR=2.67; 95%CI: 1.17-6.14, p=0.020). On ROC curves, GDF15 was found to be the best preoperative biomarker to predict AKI (AUC 0.83; CI 0.75-0.89), compared with eGFR (AUC 0.67; 95%CI 0.59-0.75 p=0.003) and NT-proBNP (AUC 0.62; CI 0.51-0.72 p<0.001). GDF15 level was also significantly better than the EuroSCORE in predicting AKI (AUC 0.62, 95%CI 0.54-0.70 p<0.001). The predictive model including high blood pressure, diabetes, preoperative eGFR and CPB surgery was significantly improved when preoperative GDF15 was added. Preoperative GDF15 plasma levels are associated with postoperative AKI in CABG patients. Preoperative GDF15 may improve preoperative risk stratification and discrimination among candidates for surgery.