title: Pre-operative growth differentiation factor 15 as a novel biomarker of acute kidney injury after cardiac bypass surgery.
abstract: BACKGROUND
  Pre-operative GDF-15 plasma levels significantly improve the prognostic value of the EuroSCORE for mortality after cardiac surgery. However, despite the strong correlation between GDF-15 and renal function, no data are available regarding the potential interest of pre-operative GDF-15 levels to improve the prediction of acute kidney injury (AKI) after cardiac artery bypass graft (CABG) surgery.
  
  
  METHODS
  All patients operated on by 2 surgeons for CABG surgery at our university hospital from September 2011 to March 2013 were screened for participation in this prospective, observational study.
  
  
  METHODS
  age <18years or >80years, previous atrial fibrillation/flutter, previous severe renal failure, previous cardiac surgery, emergency surgery. AKI was defined according to KDIGO criteria. GDF-15 levels in plasma were measured before induction and 12h after surgery.
  
  
  RESULTS
  134 patients were included in this study. 42 (31%) developed post-operative AKI. AKI patients had a significantly higher pre-operative log-GDF-15 level (OR=3.64; 95% CI=1.41-9.40, p=0.008), a lower pre-operative eGFR (OR=0.98; 95% CI=0.96-0.99; p=0.026), and most often underwent on-pump surgery (OR=2.60; 95% CI=1.14-5.96, p=0.024). On ROC curves, GDF-15 before induction was found to be the best pre-operative 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. Pre-operative GDF-15 was also significantly better than the EuroSCORE in predicting AKI (AUC 0.62, 95% CI=0.54-0.70), p<0.001.
  
  
  CONCLUSIONS
  Pre-operative GDF-15 plasma levels are associated with post-operative AKI in CABG patients. If confirmed in larger cohorts, pre-operative GDF-15 may be of value to improve pre-operative risk stratification among candidates for surgery.
authors.affiliation: University Hospital, Department of Cardiology, Dijon, France; INSERM U866, LPPCM, Dijon, France. Electronic address: charles.guenancia@chu-dijon.fr.
authors.forename: Charles
authors.initials: C
authors.lastname: Guenancia
authors.affiliation: INSERM U866, LPPCM, Dijon, France; University Hospital, Department of Anaesthesiology, Dijon, France.
authors.forename: Abdelkader
authors.initials: A
authors.lastname: Kahli
authors.affiliation: University Hospital, Department of Cardiology, Dijon, France; CNRS, UMR 5158, Le2I, Dijon, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Laurent
authors.affiliation: University Hospital, Department of Cardiology, Dijon, France; INSERM U866, LPPCM, Dijon, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Hachet
authors.affiliation: University Hospital, Department of Cardiothoracic Surgery, Dijon, France.
authors.forename: Ghislain
authors.initials: G
authors.lastname: Malapert
authors.affiliation: University Hospital, Department of Anaesthesiology, Dijon, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Grosjean
authors.affiliation: University Hospital, Department of Anaesthesiology, Dijon, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Girard
authors.affiliation: INSERM U866, LPPCM, Dijon, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Vergely
authors.affiliation: University Hospital, Department of Cardiothoracic Surgery, Dijon, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bouchot
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D055436:Growth Differentiation Factor 15 / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D055436:Growth Differentiation Factor 15
keywords: Acute kidney injury; Cardiac surgery; Cardiopulmonary bypass; GDF-15; Off-pump; Risk stratification