NEW YORK (Reuters Health) – Administering acetylcysteine to patients before and after they undergo coronary or peripheral angiography does not reduce the occurrence of contrast-induced nephropathy, according to the results of a large randomized trial conducted in Brazil.
“These findings have important implications for clinical practice and may prevent unnecessary procedure delays and health expenditures associated with the administration of acetylcysteine,” the authors comment in their report in Circulation published online August 22.
Dr. Otavio Berwanger, with Hospital do Coracao in Sao Paulo, and colleagues note that the use of acetylcysteine to prevent acute renal injury by iodinated contrast agents is based on its antioxidant and hemodynamic effects in the kidney. However, most clinical trials testing its efficacy have been small or of poor quality, and results have varied widely.
To address these issues, the team conducted a 46-site randomized trial of acetylcysteine versus placebo in 2308 patients undergoing angiography and who had at least one risk factor for contrast-induced nephropathy: ie, age over 70, renal impairment, diabetes, heart failure or hypotension.
Patients were given two doses of 1200 mg acetylcysteine or placebo before the procedure and two doses afterwards.
The primary endpoint of acute kidney injury, defined as a 25% elevation of serum creatinine above baseline between 48 and 96 hours after angiography, occurred in 12.7% of both the acetylcysteine group and the placebo group (relative risk, 1.00; p=0.97), the researchers found.
The secondary endpoint of the composite outcome of death or need for dialysis at 30 days was 2.2% in the acetylcysteine group and 2.3% in the placebo group (hazard ratio, 0.97; p=0.92), the report indicates.
Furthermore, acetylcysteine was not associated with any benefit in any of the subgroups analyzed, including those with renal impairment.
The investigators also conducted a meta-analysis of their results in the context of 45 other related trials and found “a huge variation in the effect on contrast-induced acute kidney injury, although those with adequate methodological criteria did not show any clinical benefit of acetylcysteine.”
Dr. Berwanger and colleagues conclude, “On the basis of our results, we do not recommend routine use of acetylcysteine for patients undergoing angiography.”