title: Preoperative renin-angiotensin system inhibitors use linked to reduced acute kidney injury: a systematic review and meta-analysis.
abstract: BACKGROUND
  Previous trials of interventions to prevent acute kidney injury (AKI) have been unsuccessful and additional interventions are needed. Existing reviews of preoperative renin-angiotensin system (RAS) inhibitors have suggested harm. We included more recent studies and conducted this meta-analysis to evaluate the risk of postoperative AKI in patients who received preoperative RAS inhibitors.
  
  
  METHODS
  A literature search was performed using MEDLINE, EMBASE and Cochrane Database of Systematic Reviews from inception through October, 2014. Studies that reported relative risks, odds ratios or hazard ratios comparing the AKI risk in patients who received preoperative RAS inhibitors versus those who did not were included. We performed the prespecified sensitivity analysis including only propensity score-based studies. Mortality risk was evaluated among the studies that reported AKI outcome. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.
  
  
  RESULTS
  Twenty-four studies (1 randomized controlled trial and 23 cohort studies) with 102 675 patients were included in the analysis to assess the risk of postoperative AKI and preoperative RAS inhibitors use. The pooled RR of AKI in patients receiving RAS inhibitors was 1.05 (95% CI: 0.92-1.20). The meta-analysis of the RCT and 11 studies with propensity score analysis demonstrated the pooled RR of AKI in patients receiving RAS inhibitors of 0.92 (95% CI: 0.85-0.99). Within the selected studies, preoperative RAS inhibitor therapy was not associated with a significant increase or decrease in mortality (RR: 0.93; 95% CI: 0.80-1.09).
  
  
  CONCLUSIONS
  Our meta-analysis demonstrates an association between preoperative RAS inhibitor treatment and lower incidence of AKI.
authors: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors: Wisit
authors: W
authors: Cheungpasitporn
authors: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors: Charat
authors: C
authors: Thongprayoon
authors: Division of Pulmonary and Critical Care Medicine,Mayo Clinic, Rochester, MN, USA.
authors: Narat
authors: N
authors: Srivali
authors: University College Cork, Cork, Ireland.
authors: Oisin A
authors: OA
authors: O'Corragain
authors: SUNY Upstate Medical University, Syracuse, NY, USA.
authors: Peter J
authors: PJ
authors: Edmonds
authors: Division of Rheumatology, Mayo Clinic, Rochester, MN, USA.
authors: Patompong
authors: P
authors: Ungprasert
authors: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors: Wonngarm
authors: W
authors: Kittanamongkolchai
authors: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors: Stephen B
authors: SB
authors: Erickson
mesh_terms: D058186:Acute Kidney Injury / Q000188:drug therapy*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D006801:Humans; D012084:Renin-Angiotensin System / Q000187:drug effects*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors
keywords: acute kidney injury; angiotensin II receptor blockers; angiotensin-converting enzyme inhibitors; meta-analysis; renin–angiotensin system inhibitors