title: Acute Kidney Injury in Cardiorenal Syndrome Type 1 Patients: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  We evaluated the epidemiology and outcome of acute kidney injury (AKI) in patients with cardiorenal syndrome type 1 (CRS-1) and its subgroups: acute heart failure (AHF), acute coronary syndrome (ACS) and after cardiac surgery (CS).
  
  
  CONCLUSIONS
  We performed a systematic review and meta-analysis. CRS-1 was defined by AKI (based on RIFLE, AKIN and KDIGO), worsening renal failure (WRF) and renal replacement therapy (RRT). We investigated the three most common clinical causes of CRS-1: AHF, ACS and CS. Out of 332 potential papers, 64 were eligible - with AKI used in 41 studies, WRF in 25 and RRT in 20. The occurrence rate of CRS-1, defined by AKI, WRF and RRT, was 25.4, 22.4 and 2.6%, respectively. AHF patients had a higher occurrence rate of CRS-1 compared to ACS and CS patients (AKI: 47.4 vs. 14.9 vs. 22.1%), but RRT was evenly distributed among the types of acute cardiac disease. AKI was associated with an increased mortality rate (risk ratio = 5.14, 95% CI 3.81-6.94; 24 studies and 35,227 patients), a longer length of stay in the intensive care unit [LOSICU] (median duration = 1.37 days, 95% CI 0.41-2.33; 9 studies and 10,758 patients) and a longer LOS in hospital [LOShosp] (median duration = 3.94 days, 95% CI 1.74-6.15; 8 studies and 35,227 patients). Increasing AKI severity was associated with worse outcomes. The impact of CRS-1 defined by AKI on mortality was greatest in CS patients. RRT had an even greater impact compared to AKI (mortality risk ratio = 9.2, median duration of LOSICU = 10.6 days and that of LOShosp = 20.2 days).
  
  
  CONCLUSIONS
  Of all included patients, almost one quarter developed AKI and approximately 3% needed RRT. AHF patients experienced the highest occurrence rate of AKI, but the impact on mortality was greatest in CS patients.
authors.affiliation: Departments of Intensive Care Medicine, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Vandenberghe
authors.affiliation: Departments of Cardiology, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Gevaert
authors.affiliation: Centre for Critical Care Nephrology, University of Pittsburgh, Pa., USA; The Clinical Research, Investigation, and Systems Modelling of Acute Illness (CRISMA) Centre, Department of Critical Care Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, Pa., USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Kellum
authors.affiliation: Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alta., Canada.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
authors.affiliation: Departments of Intensive Care Medicine, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Harlinde
authors.initials: H
authors.lastname: Peperstraete
authors.affiliation: Departments of Intensive Care Medicine, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Herck
authors.affiliation: Departments of Intensive Care Medicine, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Decruyenaere
authors.affiliation: Departments of Intensive Care Medicine, Ghent University Hospital, Ghent University, Ghent, Belgium; Research Foundation-Flanders (FWO), Brussels, Belgium; The Clinical Research, Investigation, and Systems Modelling of Acute Illness (CRISMA) Centre, Department of Critical Care Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, Pa., USA.
authors.forename: Eric A J
authors.initials: EA
authors.lastname: Hoste
keywords: Acute kidney injury; Cardiorenal syndrome; Meta-analysis; Type 1