N-acetylcysteine: short-term clinical benefits after coronary angiography in high-risk renal patients.

INTRODUCTION AND OBJECTIVES: Previous studies on the role of N-acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography and on the drug's long-term effects have produced contradictory findings. The aim of this study was to clarify the benefits of N-acetylcysteine.

METHODS: A prospective, randomized, double-blind study was carried out in patients with chronic renal failure (plasma creatinine= >or=1.4 mg/dL) who underwent coronary angiography. This study concerns the second arm of the main study. Findings on the arm involving patients with normal renal function have been published previously. As before, patients were randomly assigned to receive either N-acetylcysteine, 600 mg every 12 h intravenously, or placebo. The primary end-point was the development of contrast-induced nephropathy.

RESULTS: The study included 81 patients (39 on N-acetylcysteine, 42 on placebo) with comparable baseline clinical characteristics. The overall incidence of contrast-induced nephropathy was 14.8% (12 patients): 5.1% (2 patients) in the N-acetylcysteine group and 23.8% (10 patients) in the placebo group (odds ratio [OR]=0.17; 95% confidence interval [CI], 0.03-0.84; P=.027). One patient (1.2%) in the latter group required dialysis while in the coronary unit. Multivariate analysis showed that N-acetylcysteine was an independent protective factor against the composite end-point of contrast-induced nephropathy, need for dialysis and mortality during the coronary unit stay (OR=0.20; 95% CI, 0.04-0.97; P=.04). Nevertheless, no significant difference was observed between the N-acetylcysteine and placebo groups in the rates of in-hospital (10.3% vs. 16.7%, respectively) or 1-year mortality (15.4% vs. 21.4%, respectively).

CONCLUSIONS: Prophylactic administration of N-acetylcysteine provided significant short-term clinical benefits in high-risk renal patients who underwent coronary angiography.