title: Statin initiation and acute kidney injury following elective cardiovascular surgery: a population cohort study in Denmark†.
abstract: OBJECTIVE
  Acute kidney injury (AKI) is a serious complication of cardiac surgery. Statins may prevent post-surgical AKI, yet methodological concerns about existing studies raise questions about the magnitude of a protective effect. We sought to determine the effect of initiating a statin prior to elective cardiac surgery on post-surgical AKI in a regional Danish surgical cohort.
  
  
  METHODS
  We identified adults who underwent cardiac surgery during 2006-11 using the Western Denmark Heart Registry. Presurgical medication use, pre- and post-surgical serum creatinine (sCr) measures, and other patient characteristics were obtained from Danish population-based registries. Post-surgical AKI was assessed using sCr measures within 5 days of surgery. The adjusted risk ratio (RR) of AKI and 95% confidence interval (CI) were estimated for patients who initiated a statin within 100 days prior to surgery compared with patients without prior statin use; long-term statin users were excluded to reduce healthy-user bias. Subanalyses were stratified by surgery type: coronary artery bypass grafting (CABG) and non-CABG surgeries.
  
  
  RESULTS
  We identified 1929 CABG and 1775 non-CABG patients. AKI occurred in 25% of CABG and 28% of non-CABG surgeries, and in 29% of the non-users and 21% of the statin initiators. Half of CABG patients and 9% of non-CABG patients initiated a statin prior to surgery. The adjusted RRs for the effect of statin initiation on AKI were as follows: all surgeries combined, RR = 0.86 (95% CI: 0.74, 0.98); CABG, RR = 0.88 (0.74, 1.05); non-CABG RR = 0.87 (0.68, 1.11).
  
  
  CONCLUSIONS
  Presurgical statin initiation is associated with a reduction in AKI risk after cardiac surgery.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA blayton@unc.edu.
authors.forename: James Bradley
authors.initials: JB
authors.lastname: Layton
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Malene K
authors.initials: MK
authors.lastname: Hansen
authors.affiliation: Department of Anaesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Jakobsen
authors.affiliation: UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Abhijit V
authors.initials: AV
authors.lastname: Kshirsagar
authors.affiliation: Department of Cardiothoracic Surgery and Clinical Medicine, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Andreasen
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Vibeke E
authors.initials: VE
authors.lastname: Hjortdal
authors.affiliation: Department of Anesthesia and Intensive Care Medicine, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Bodil S
authors.initials: BS
authors.lastname: Rasmussen
authors.affiliation: Division of Cardiology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Simpson
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Maurice Alan
authors.initials: MA
authors.lastname: Brookhart
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Christiansen
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology*; D000368:Aged; D000369:Aged, 80 and over; D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects* / Q000706:statistics & numerical data*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use*; D008297:Male; D059035:Perioperative Period; D012306:Risk
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors
keywords: Acute kidney injury; Acute renal failure; Perioperative management; Surgical outcomes