title: Urinary cystatin C and acute kidney injury after cardiac surgery.
abstract: BACKGROUND
  Acute kidney injury (AKI) is common after cardiac surgery and is associated with adverse patient outcomes. Urinary cystatin C (CysC) level is a biomarker of proximal tubule function and may increase earlier in AKI than serum creatinine level.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  The TRIBE AKI (Translational Research Investigating Biomarker Endpoints in AKI) Consortium prospectively enrolled 1,203 adults and 299 children and adolescents at 8 institutions in 2007-2009.
  
  
  METHODS
  Urinary CysC (in milligrams per liter) within the first 12 hours after surgery.
  
  
  RESULTS
  Serum creatinine-based AKI was defined as AKI Network stage 1 (mild AKI) and doubling of serum creatinine from the preoperative value or need for dialysis during hospitalization (severe AKI).
  
  
  METHODS
  Analyses were adjusted for characteristics used clinically for AKI risk stratification, including age, sex, race, estimated glomerular filtration rate, diabetes, hypertension, heart failure, nonelective surgery, cardiac catheterization within 72 hours, type of surgery, myocardial infarction, and cardiopulmonary bypass time longer than 120 minutes.
  
  
  RESULTS
  Urinary CysC level measured in the early postoperative period (0-6 and 6-12 hours postoperatively) correlated with both mild and severe AKI in adults and children. However, after analyses were adjusted for other factors, the effect was attenuated for both forms of AKI in both cohorts.
  
  
  CONCLUSIONS
  Limited numbers of patients with severe AKI and in-hospital dialysis treatment.
  
  
  CONCLUSIONS
  Urinary CysC values are not associated significantly with the development of AKI after cardiac surgery in adults and children.
authors: Section of Nephrology, Department of Medicine, University of Chicago, Pritzker School of Medicine, Chicago, IL, USA.
authors: Jay L
authors: JL
authors: Koyner
authors: Amit X
authors: AX
authors: Garg
authors: Michael G
authors: MG
authors: Shlipak
authors: Uptal D
authors: UD
authors: Patel
authors: Kyaw
authors: K
authors: Sint
authors: Kwangik
authors: K
authors: Hong
authors: Prasad
authors: P
authors: Devarajan
authors: Charles L
authors: CL
authors: Edelstein
authors: Michael
authors: M
authors: Zappitelli
authors: Heather
authors: H
authors: Thiessen-Philbrook
authors: Chirag R
authors: CR
authors: Parikh
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology / Q000652:urine*; D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006331:Heart Diseases / Q000601:surgery; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine