title: The effect of N-acetylcysteine on the incidence of contrast-induced kidney injury: A systematic review and trial sequential analysis.
abstract: BACKGROUND
  There have been a myriad of studies investigating the effectiveness of N-acetylcysteine (NAC) in the prevention of contrast induced nephropathy (CIN) in patients undergoing coronary angiography (CAG) with or without percutaneous coronary intervention (PCI). However the consensus is still out about the effectiveness of NAC pre-treatment due to vastly mixed results amongst the literature.
  
  
  OBJECTIVE
  The aim of this study was to conduct a meta-analysis and trial sequential analysis to determine the effects of pre-operative NAC in lowering the incidence of CIN in patients undergoing CAG and/or PCI.
  
  
  METHODS
  A systematic literature search was performed to include all randomized controlled trials (RCTs) comparing NAC versus control as pretreatment for CAG and/or PCI. A traditional meta-analysis and several subgroup analyses were conducted using traditional meta-analysis with relative risk (RR), trial sequential analysis, and meta-regression analysis.
  
  
  RESULTS
  43 RCTs met our inclusion criteria giving a total of 3277 patients in both control and treatment arms. There was a significant reduction in the risk of CIN in the NAC treated group compared to control (OR 0.666; 95% CI, 0.532-0.834; I2=40.11%; p=0.004). Trial sequential analysis, using a relative risk reduction threshold of 15%, indicates that the evidence is firm.
  
  
  CONCLUSIONS
  The results of the present paper support the use of NAC in the prevention of CIN in patients undergoing CAG±PCI. Future studies should focus on the benefits of NAC amongst subgroups of high-risk patients.
authors.affiliation: Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Nelson
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Westmead Hospital, Sydney, Australia.
authors.forename: Pierre
authors.initials: P
authors.lastname: Qian
authors.affiliation: Faculty of Medicine, University of Western Sydney, Sydney, Australia.
authors.forename: Shejil
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Tristan D
authors.initials: TD
authors.lastname: Yan
authors.affiliation: Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia; Department of Cardiology, Westmead Hospital, Sydney, Australia. Electronic address: kphan.vc@gmail.com.
authors.forename: Kevin
authors.initials: K
authors.lastname: Phan
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000188:drug therapy* / Q000453:epidemiology; D003287:Contrast Media / Q000009:adverse effects*; D016166:Free Radical Scavengers / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D016166:Free Radical Scavengers; D000111:Acetylcysteine
keywords: Acute kidney injury; Angioplasty; Contrast; Meta-analysis; Percutaneous coronary intervention; Trial sequential analysis