title: A Preoperative Multimarker Approach to Evaluate Acute Kidney Injury After Cardiac Surgery.
abstract: OBJECTIVE
  To investigate whether a multimarker strategy combining preoperative biomarkers representing distinct pathophysiologic pathways enhances preoperative risk assessment of acute kidney injury after cardiac surgery (CSA-AKI) and increases knowledge of underlying pathogenesis.
  
  
  METHODS
  Prospective, cohort study.
  
  
  METHODS
  Single-center tertiary referral hospital.
  
  
  METHODS
  The study comprised 1,015 adults undergoing cardiac surgery with cardiopulmonary bypass.
  
  
  METHODS
  CSA-AKI was defined as≥50% increase in serum creatinine concentration, absolute increase≥26 µmol/L, or new requirement for dialysis. Preoperative and perioperative information until hospital discharge was recorded. Preoperative plasma levels of C-reactive protein, terminal complement complex, neopterin, lactoferrin, N-terminal pro-brain natriuretic peptide, and cystatin C were determined using enzyme immunoassays. Biomarkers were selected based on causal hypotheses of underlying mechanisms and were related to inflammatory, hemodynamic, or renal signaling pathways.
  
  
  RESULTS
  One hundred patients (9.9%) developed CSA-AKI. Higher baseline plasma concentrations of neopterin and N-terminal pro-brain natriuretic peptide were associated independently with CSA-AKI (p = 0.04 and p<0.001, respectively). Lower baseline plasma lactoferrin concentrations were observed in patients with CSA-AKI (p = 0.05). Compared with clinical risk assessment, addition of these biomarkers provided a slight, but significant, increment in predictive utility (area under the curve 0.81-0.83, likelihood ratio test p<0.001). A net of 12% of patients were reclassified correctly, and improved prediction was demonstrated, especially in patients with intermediate risk (56% correct reclassification).
  
  
  CONCLUSIONS
  Preoperative hemodynamic, renal, and immunologic function play central roles in the pathogenesis of CSA-AKI. These findings add evidence to the potential of a multimarker approach to improve preoperative prediction of CSA-AKI.
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway; Department of Cardiothoracic Anesthesia and Intensive Care, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Tone B
authors.initials: TB
authors.lastname: Enger
authors.affiliation: Department of Circulation and Medical Imaging, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway; Clinic of Anesthesia and Intensive Care, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Hilde
authors.initials: H
authors.lastname: Pleym
authors.affiliation: Department of Cardiothoracic Anesthesia and Intensive Care, St. Olavs University Hospital, Trondheim, Norway; Department of Circulation and Medical Imaging, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Roar
authors.initials: R
authors.lastname: Stenseth
authors.affiliation: Department of Cardiothoracic Anesthesia and Intensive Care, St. Olavs University Hospital, Trondheim, Norway; Department of Circulation and Medical Imaging, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Guri
authors.initials: G
authors.lastname: Greiff
authors.affiliation: Department of Circulation and Medical Imaging, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway; Clinic of Cardiothoracic Surgery, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wahba
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, NTNU-Norwegian University of Science and Technology, Trondheim, Norway; Department of Immunology and Transfusion Medicine, St. Olavs University Hospital, Trondheim, Norway. Electronic address: vibeke.videm@ntnu.no.
authors.forename: Vibeke
authors.initials: V
authors.lastname: Videm
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000639:trends; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D011183:Postoperative Complications / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies
chemical_list: D015415:Biomarkers
keywords: acute kidney injury; cardiac surgery; preoperative biomarkers; risk prediction