title: Efficacy of N-acetylcysteine in preventing renal injury after heart surgery: a systematic review of randomized trials.
abstract: OBJECTIVE
  The aim of this study was to assess whether perioperative N-acetylcysteine (NAC), an antioxidant, prevents acute renal injury (ARI) after cardiac surgery.
  
  
  RESULTS
  We performed a systematic review of randomized controlled trials (RCTs) of NAC in adult cardiac surgery patients. The RCTs were identified by searching MEDLINE (1960-2008), clinicaltrials.gov website, and hand-searching references of relevant publications. Primary outcome was ARI (absolute increase >0.5 mg/dL or relative increase >25%, in serum creatinine from baseline within 5 days after surgery). Random effects model was used to perform a meta-analysis. Forest plots and I(2) test were used to assess heterogeneity among studies. Ten RCTs (n = 1163 patients) were included. Mean age was 70 +/- 7.4 years, 71% were male, and 66% underwent coronary artery bypass surgery. N-Acetylcysteine did not reduce ARI incidence [35% NAC vs. 37% placebo; relative risk (RR) 0.91, 95% CI 0.79-1.06, P = 0.24]. Overall, 3.3% of patients required haemodialysis (NAC vs. placebo; RR = 1.13, 95% CI 0.59-2.17) and 3% died (RR = 1.10, 95% CI 0.56-2.16). There was a trend towards reduced ARI incidence among patients with baseline chronic kidney disease assigned to intravenous NAC (RR = 0.80, 95% CI 0.64-1.01, P = 0.06).
  
  
  CONCLUSIONS
  This meta-analysis of RCTs showed that prophylactic perioperative NAC in cardiac surgery does not reduce ARI, haemodialysis, or death.
authors.affiliation: Division of Cardiology (111 C), Minneapolis Veterans Affairs Medical Center, The Minneapolis VA Center for Chronic Disease Outcomes Research, and the University of Minnesota, One Veterans Drive, Minneapolis, MN 55417, USA. adaba001@umn.edu
authors.forename: A Selcuk
authors.initials: AS
authors.lastname: Adabag
authors.forename: Areef
authors.initials: A
authors.lastname: Ishani
authors.forename: Hanna E
authors.initials: HE
authors.lastname: Bloomfield
authors.forename: Anita K
authors.initials: AK
authors.lastname: Ngo
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wilt
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000517:prevention & control*; D000368:Aged; D000975:Antioxidants / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D019990:Perioperative Care; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D000975:Antioxidants; D000111:Acetylcysteine