title: Acetylcysteine for prevention of contrast-induced nephropathy after intravascular angiography: a systematic review and meta-analysis.
abstract: BACKGROUND
  Contrast-induced nephropathy is an important cause of acute renal failure. We assess the efficacy of acetylcysteine for prevention of contrast-induced nephropathy among patients undergoing intravascular angiography.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of randomized controlled trials comparing prophylactic acetylcysteine plus hydration versus hydration alone in patients undergoing intravascular angiography. Studies were identified by searching MEDLINE, EMBASE, and CENTRAL databases. Our main outcome measures were the risk of contrast-induced nephropathy and the difference in serum creatinine between acetylcysteine and control groups at 48 h.
  
  
  RESULTS
  Fourteen studies involving 1261 patients were identified and included for analysis, and findings were heterogeneous across studies. Acetylcysteine was associated with a significantly reduced incidence of contrast-induced nephropathy in five studies, and no difference in the other nine (with a trend toward a higher incidence in six of the latter studies). The pooled odds ratio for contrast-induced nephropathy with acetylcysteine relative to control was 0.54 (95% CI, 0.32-0.91, p = 0.02) and the pooled estimate of difference in 48-h serum creatinine for acetylcysteine relative to control was -7.2 mumol/L (95% CI -19.7 to 5.3, p = 0.26). These pooled values need to be interpreted cautiously because of the heterogeneity across studies, and due to evidence of publication bias. Meta-regression suggested that the heterogeneity might be partially explained by whether the angiography was performed electively or as emergency.
  
  
  CONCLUSIONS
  These findings indicate that published studies of acetylcysteine for prevention of contrast-induced nephropathy yield inconsistent results. The efficacy of acetylcysteine will remain uncertain unless a large well-designed multi-center trial is performed.
authors.affiliation: Department of Critical Care Medicine, Calgary Health Region, Calgary, Canada. smbagsha@ucaglary.ca <smbagsha@ucaglary.ca>
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
authors.forename: William A
authors.initials: WA
authors.lastname: Ghali
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D000792:Angiography / Q000009:adverse effects; D003287:Contrast Media / Q000009:adverse effects*; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced / Q000517:prevention & control*
chemical_list: D003287:Contrast Media; D000111:Acetylcysteine