title: Role of N-acetylcysteine in prevention of contrast-induced nephropathy after cardiovascular procedures: a meta-analysis.
abstract: BACKGROUND
  Contrast-induced nephropathy is one of the common causes of acute renal insufficiency after cardiovascular procedures.
  
  
  OBJECTIVE
  The objective of this paper was to analyze the published data on the usefulness of N-acetylcysteine in the prevention of contrast-induced nephropathy after these procedures.
  
  
  METHODS
  Trials were selected if they were prospective, randomized, controlled, had selected patients with impaired renal function, used low-osmolality, nonionic contrast media intra-arterially, administered a total of four doses of N-acetylcysteine in addition to intravenous saline hydration, and had contrast-induced nephropathy as their primary outcome. Contrast-induced nephropathy was defined as an increase in serum creatinine concentration by >0.5 mg/dl or a 25% increase above baseline at or within 48 h post procedure. Meta-analysis was performed using the Fisher's Combined Test with a measure of effect size. The magnitude of the N-acetylcysteine effect was estimated using random-effects models. Homogeneity was evaluated using the chi-square test of homogeneity and standard Q statistic. Reporting bias was explored by the Rosenthal method.
  
  
  RESULTS
  The Fisher's Combined Test was significant at p < 0.005 in favor of N-acetylcysteine. The size of the N-acetylcysteine effect was to reduce contrast-induced nephropathy by 20%. There was a 62% relative risk reduction in contrast-induced nephropathy with N-acetylcysteine using a fixed-effects model, and a 70% relative risk reduction using the random-effects model. In addition, we found that 27 unpublished trials showing no effects of N-acetylcysteine would exist to overturn the combined significance of p < 0.005 of the five trials in our meta-analysis.
  
  
  CONCLUSIONS
  Oral administration of N-acetylcysteine in addition to intravenous saline hydration has a beneficial effect in the prevention of contrast-induced nephropathy after cardiovascular procedures in patients with impaired renal function.
authors.affiliation: Division of Cardiology, Beth Israel Medical Center, New York, New York, USA.
authors.forename: Deepika
authors.initials: D
authors.lastname: Misra
authors.forename: Keith
authors.initials: K
authors.lastname: Leibowitz
authors.forename: Ramesh M
authors.initials: RM
authors.lastname: Gowda
authors.forename: Michael
authors.initials: M
authors.lastname: Shapiro
authors.forename: Ijaz A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D000111:Acetylcysteine / Q000008:administration & dosage / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000517:prevention & control*; D000284:Administration, Oral; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects; D006328:Cardiac Catheterization / Q000009:adverse effects; D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects*; D003287:Contrast Media / Q000009:adverse effects*; D017023:Coronary Angiography / Q000009:adverse effects; D006801:Humans
chemical_list: D003287:Contrast Media; D000111:Acetylcysteine