Renal toxicity is an important complication of coronary angiography, often resulting in prolonged hospitalization. Use of acetylcysteine has been shown to prevent contrast-mediated acute renal dysfunction in patients with chronic renal insufficiency. The postulated mechanisms include antioxidant and vasodilatory effects. Kay and colleagues conducted a randomized, double-blind, controlled trial to measure the effects of acetylcysteine on renal function in renally impaired patients undergoing coronary arteriography and related interventional procedures.

Two hundred patients with a serum creatinine level of 1.2 mg per dL (106 mmol per L) or higher or a creatinine clearance of less than 60 mL per minute (1.0 mL per second) were randomly assigned to receive acetylcysteine or placebo. Serum creatinine and urea levels were measured at the time of admission, and at 24 hours, 48 hours, and seven days following the administration of contrast medium. The 24-hour urine creatinine collections were made at the time of admission, and at 48 hours and seven days after contrast administration.

Patients receiving acetylcysteine experienced a contrast-induced reduction in renal function two thirds less often (12 percent versus 4 percent with placebo). Mean serum creatinine concentration decreased significantly, from 1.35 to 1.22 mg per dL (119.3 to 107.8 mmol per L) in the acetylcysteine group at day 2, compared with 1.36 to 1.38 mg per dL (120.2 to 122 mmol per L) in the control group. Creatinine clearance increased significantly in the acetylcysteine group, from 44.8 to 58.9 mL per minute (0.75 to 1.0 mL per second) at day 2 after angiography, whereas the only significant change in the control group's creatinine clearance was on day 7. The average length of hospitalization was reduced by one half day in the acetylcysteine group. No patient in either group required dialysis and, except for one patient in the control group, none suffered adverse cardiac events.

The authors conclude that acetylcysteine prevents contrast toxicity in patients with moderate chronic renal insufficiency who are undergoing coronary diagnostic or intervention procedures. Actual morbidity and mortality outcomes have yet to be studied.