N-acetylcysteine and contrast-induced nephropathy in primary angioplasty.

BACKGROUND Patients with acute myocardial infarction undergoing primary angioplasty are at high risk for contrast-medium-induced nephropathy because of hemodynamic instability, the need for a high volume of contrast medium, and the lack of effective prophylaxis. We investigated the antioxidant N-acetylcysteine for the prevention of contrast-medium-induced nephropathy in patients undergoing primary angioplasty. METHODS We randomly assigned 354 consecutive patients undergoing primary angioplasty to one of three groups: 116 patients were assigned to a standard dose of N-acetylcysteine (a 600-mg intravenous bolus before primary angioplasty and 600 mg orally twice daily for the 48 hours after angioplasty), 119 patients to a double dose of N-acetylcysteine (a 1200-mg intravenous bolus and 1200 mg orally twice daily for the 48 hours after intervention), and 119 patients to placebo. RESULTS The serum creatinine concentration increased 25 percent or more from baseline after primary angioplasty in 39 of the control patients (33 percent), 17 of the patients receiving standard-dose N-acetylcysteine (15 percent), and 10 patients receiving high-dose N-acetylcysteine (8 percent, P<0.001). Overall in-hospital mortality was higher in patients with contrast-medium-induced nephropathy than in those without such nephropathy (26 percent vs. 1 percent, P<0.001). Thirteen patients (11 percent) in the control group died, as did five (4 percent) in the standard-dose N-acetylcysteine group and three (3 percent) in the high-dose N-acetylcysteine group (P=0.02). The rate for the composite end point of death, acute renal failure requiring temporary renal-replacement therapy, or the need for mechanical ventilation was 21 (18 percent), 8 (7 percent), and 6 (5 percent) in the three groups, respectively (P=0.002). CONCLUSIONS Intravenous and oral N-acetylcysteine may prevent contrast-medium-induced nephropathy with a dose-dependent effect in patients treated with primary angioplasty and may improve hospital outcome. (ClinicalTrials.gov number, NCT00237614[ClinicalTrials.gov]).