To study the usefulness of N-acetylcysteine in prevention of contrast-induced nephropathy after the intra-arterial administration of contrast for cardiac procedures.
We performed a meta-analysis of five prospective, randomized controlled trials on the role of periprocedure administration of N-acetylcysteine for the prevention of contrast-induced nephropathy after cardiac procedures. All of these trials included patients with impaired renal function, used low-osmolality non-ionic contrast media intra-arterially, administered a total of four doses of N-acetylcysteine, and had contrast-induced nephropathy as their primary outcome. The contrast-induced nephropathy was defined as an increase in serum creatinine concentration by >0.5mg/dl or 25% increase above baseline at or within 48 hours post procedure. Meta-analysis was performed using the Fisher Combined Test with a measure of effect size. The magnitude of the N-acetylcysteine effect was estimated using the random-effects model. Homogeneity was evaluated using the chi-square test of homogeneity and the standard Q statistic. To explore the presence of reporting bias Rosenthal’s method was used to calculate the number of negative studies that would have to exist in order to invalidate a significant overall p value.
The Fisher 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 30% relative risk reduction of contrast-induced nephropathy in patients given N-acetylcysteine using the random-effects model. In addition, we found that 27 unpublished studies at a p=0.05 showing no effects of N-acetylcysteine would have to be tracked down to overturn the combined significance of p<0.005 of the five studies in our meta-analysis.
The oral administration of N-acetylcysteine has a beneficial effect in prevention of contrast-induced nephropathy post cardiac procedures in patients with impaired renal function.
The increased morbidity and higher health care costs associated with contrast-induced nephropathy can be effectively reduced by using N-acetylcysteine, which has minimal cost and lacks significant side effects.
K. Leibowitz, None.