title: Urinary, Plasma, and Serum Biomarkers' Utility for Predicting Acute Kidney Injury Associated With Cardiac Surgery in Adults: A Meta-analysis.
abstract: BACKGROUND
  Early accurate detection of acute kidney injury (AKI) occurring after cardiac surgery may improve morbidity and mortality. Although several novel biomarkers have been developed for the early detection of AKI, their clinical utility in the critical intraoperative and immediate postoperative period remains unclear.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  Adult patients having cardiac surgery.
  
  
  METHODS
  EMBASE, CINAHL, Cochrane Library, Scopus, and PubMed from January 1990 until January 2015 were systematically searched for cohort studies reporting the utility of novel biomarkers for the early diagnosis of AKI after adult cardiac surgery. Reviewers extracted data for study design, population, timing of biomarker measurement and AKI occurrence, biomarker performance (area under the receiver operating characteristic curve [AUROC]), and risk of bias.
  
  
  METHODS
  Novel urine, plasma, and serum AKI biomarkers, measured intraoperatively and in the early postoperative period (<24 hours).
  
  
  METHODS
  AKI was defined according to the RIFLE, AKIN, or 2012 KDIGO criteria.
  
  
  RESULTS
  We found 28 studies reporting intraoperative and/or early postoperative measurement of urine (n=23 studies) or plasma or serum (n=12 studies) biomarkers. Only 4 of these studies measured biomarkers intraoperatively. Overall, intraoperative discrimination by the urine biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury marker 1 (KIM-1) demonstrated AUROCs<0.70, whereas N-acetyl-β-d-glucosaminidase (NAG) and cystatin C had AUROCs<0.75. In the immediate 24-hour postoperative period, the urine biomarkers NGAL (16 studies), KIM-1 (6 studies), and liver-type fatty acid binding protein (6 studies) exhibited composite AUROCs of 0.69 to 0.72. The composite AUROCs for postoperative urine cystatin C, NAG, and interleukin 18 were ≤0.70. Similarly, the composite AUROCs for postoperative plasma NGAL (6 studies) and cystatin-C (5 studies) were <0.70.
  
  
  CONCLUSIONS
  Heterogeneous AKI definitions.
  
  
  CONCLUSIONS
  In adults, known urinary, plasma, and serum biomarkers of AKI possess modest discrimination at best when measured within 24 hours of cardiac surgery.
authors.affiliation: Section of Nephrology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Immunology, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Ho
authors.affiliation: Section of Nephrology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Navdeep
authors.initials: N
authors.lastname: Tangri
authors.affiliation: Section of Nephrology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Komenda
authors.affiliation: Section of Nephrology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada.
authors.forename: Amit
authors.initials: A
authors.lastname: Kaushal
authors.affiliation: Division of Nephrology, Department of Internal Medicine, University of Ottawa, Winnipeg, Manitoba, Canada.
authors.forename: Manish
authors.initials: M
authors.lastname: Sood
authors.affiliation: Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada.
authors.forename: Ranveer
authors.initials: R
authors.lastname: Brar
authors.affiliation: Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada.
authors.forename: Kamal
authors.initials: K
authors.lastname: Gill
authors.affiliation: Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Walker
authors.affiliation: Seven Oaks Hospital Library, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Kerry
authors.initials: K
authors.lastname: MacDonald
authors.affiliation: Institute of Cardiac Sciences, St. Boniface General Hospital, Winnipeg, Manitoba, Canada.
authors.forename: Brett M
authors.initials: BM
authors.lastname: Hiebert
authors.affiliation: Institute of Cardiac Sciences, St. Boniface General Hospital, Winnipeg, Manitoba, Canada; Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Rakesh C
authors.initials: RC
authors.lastname: Arora
authors.affiliation: Section of Nephrology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Seven Oaks Hospital Research Centre, Winnipeg, Manitoba, Canada. Electronic address: crigatto@sbgh.mb.ca.
authors.forename: Claudio
authors.initials: C
authors.lastname: Rigatto
mesh_terms: D000118:Acetylglucosaminidase / Q000097:blood / Q000652:urine; D058186:Acute Kidney Injury / Q000097:blood* / Q000175:diagnosis / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood / Q000652:urine; D055316:Cystatin C / Q000097:blood / Q000652:urine; D050556:Fatty Acid-Binding Proteins / Q000097:blood / Q000652:urine; D006801:Humans; D011183:Postoperative Complications / Q000097:blood* / Q000175:diagnosis / Q000652:urine*; D011237:Predictive Value of Tests
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D050556:Fatty Acid-Binding Proteins; D003404:Creatinine; D000118:Acetylglucosaminidase
keywords: Cardiopulmonary bypass; acute kidney injury; alpha-1-microglobulin (A1M); biomarker; diagnostic performance; early postoperative; hepcidin-25; intraoperative; liver-type fatty acid binding protein (L-FABP); monocyte chemoattractant protein 1 (CCL2); tumor necrosis factor alpha (TNF-α); uric acid