028: Ascorbic acid prevents contrast-mediated nephropathy in patients undergoing coronary angiography

Abstract

Radiocontrast nephropathy is associated with increased morbidity and mortality, particularly in patients with percutaneous coronary interventions. A number of agents that improve renal circulation have been clinically tested for prevention of radiocontrast nephropathy, but none of them has succeeded. Protection of renal tubular cells against oxidative stress is another approach to avoid radiocontrast nephropathy. Prophylactic effects of antioxidants such as N-acetylcysteine have been reported by several investigators, although the effectiveness of these compounds is still a matter of debate. Ascorbic acid, an antioxidant agent, a safe and not expensive medication, could be used to prevent radiocontrast nephropathy. We conducted a randomized, double-blind, placebo-controlled trial of ascorbic acid in 202 patients who underwent coronary angiography and/or intervention. The patients were randomly assigned to receive either oral Vitamin C (3 g at least 2 hours before the procedure and 2 g in the night and the morning after the procedure) or placebo, in adjunct to hydration. Serum creatinine was measured prior to and 48h after coronary angiography. The primary end-point was the occurrence of CIN, defined as an increase in serum creatinine ≥0.5 mg/dL (44.2 μmol/L) or ≥25% above baseline at 48h after exposure to contrast medium. Complete data on the outcomes were available on 202 patients, 107 of whom had received Vitamine C. There were no significant differences between the Vitamin C and placebo groups in baseline characteristics, amount of hydration, or type and volume of contrast used. CIN occurred in 11 out of 107 (10.3%) patients in the Vitamin C group and 20 out of 95 (21.1%) patients in the placebo group (P=0.032). There was detectable benefit for the prophylactic administration of oral Vitamin C over an aggressive hydration protocol in patients Undergoing Coronary Angiography or Intervention.