title: Plasma microRNA-21 for the early prediction of acute kidney injury in patients undergoing major cardiac surgery.
abstract: Acute kidney injury (AKI) is a complication after major cardiac surgery that is associated with higher rates of morbidity and mortality. MicroRNA-21 (miR-21) has been described as an early biomarker for AKI. We investigated whether miR-21 is predictive of AKI and long-term mortality after cardiac surgery.
  
  
  
  Consecutive patients (n = 115) undergoing major cardiac surgery were included. Serum creatinine was measured prior to, 4 h after, and 1, 4 and 7 days after extracorporeal circulation. Diagnosis of post-operative AKI was made in accordance with the international Kidney Disease: Improving Global Outcomes definition of AKI. Serum cystatin C and miR-21 were measured prior to and 4 h after surgery. miR-21 was determined by quantitative RT-PCR and was normalized to miRNA-39 from Caenorhabditis elegans. The median follow-up time was 2.9 years.
  
  
  
  AKI occurred in 36.5% (n = 42) of all patients. Baseline miR-21 was significantly lower in patients developing cardiac surgery-associated AKI (CSA-AKI) than in patients without CSA-AKI [0.27 (interquartile range, IQR, 0.14-0.30) versus 0.44 (IQR 0.25-0.75); P < 0.01]. Baseline miR-21 predicted CSA-AKI Stage 2/3 with an area under the curve of 0.701 [95% confidence interval (CI) 0.59-0.82; P = 0.007]. Baseline miR-21 <0.31 showed a hazard ratio of 3.11 (95% CI: 1.33-11.26) for CSA-AKI Stage 2/3. Patients with AKI Stage 2/3 had a significantly higher mortality (50 versus 10%; P = 0.0001) and dialysis rate (27 versus 11%; P = 0.038) within the 2.9-year follow-up.
  
  
  
  Our results indicate that miR-21 has the potential to identify patients at higher risk for CSA-AKI. This predictive value might be helpful in pre-procedural risk assessment and peri-procedural diagnosis and treatment.
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Luise
authors.initials: L
authors.lastname: Gaede
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Liebetrau
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Blumenstein
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Troidl
authors.affiliation: Medical Clinic I, Department of Cardiology and Angiology, University of Giessen, Gießen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Dörr
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany Department of Cardiac Surgery, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany.
authors.forename: Won-Keun
authors.initials: WK
authors.lastname: Kim
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Gottfried
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Voss
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Berkowitsch
authors.affiliation: Department of Cardiac Surgery, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.affiliation: Medical Clinic I, Department of Cardiology and Angiology, University of Giessen, Gießen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Nef
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany Medical Clinic I, Department of Cardiology and Angiology, University of Giessen, Gießen, Germany.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Hamm
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany DZHK (German Centre for Cardiovascular Research), partner site RheinMain, Bad Nauheim, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Möllmann
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D018570:Risk Assessment
chemical_list: D015415:Biomarkers; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: CSA-AKI; acute kidney injury; cardiac surgery; miR-21; microRNA-21