ACT: Acetylcysteine did not protect kidneys against contrast-induced nephropathy

American Heart Association Scientific Sessions 2010

CHICAGO — Acetylcysteine used to protect kidneys from contrast-induced nephropathy did not reduce kidney damage among Brazilian patients undergoing an angiographic procedure, according to new data from the ACT trial.

The study included 2,303 patients from 46 hospitals across Brazil who were recruited between September 2008 and July 2010. All patients had at least one of the following risk factors: diabetes; age older than 70 years; chronic renal failure; heart failure or left ventricular ejection fraction less than 0.45; or shock.

Patients were randomized to receive either acetylcysteine (n=1,172) or placebo (n=1,136). The primary endpoint was defined as contrast-induced nephropathy or a ≥25% elevation of serum creatinine above baseline 48 to 96 hours after angiography.

According to results, 12.7% of patients in both groups experienced the primary endpoint (RR=1.00; 95% CI, 0.81-1.25). Rates of both elevation >0.5 mg/dL (acetylcysteine, 3.9% vs. placebo, 3.8%) and doubling in serum creatinine (acetylcysteine, 1.1% vs. placebo, 1.5%) were also similar between groups and did not attain statistical significance.

“This is the largest study conducted [on acetylcysteine for prevention of kidney damage] and I believe that now we answered the question. Unfortunately, this drug doesn’t work,” Otavio Berwanger, MD, PhD, director, Research Institute, Hospital do Coração in Sao Paulo, Brazil, and study investigator said in an interview. “Now we need to shift to other interventions like bicarbonate and types of contrast and test that as well.”

There have been approximately 45 randomized clinical trials and 15 meta-analyses on this topic. The lessons that are learned from the evolution of evidence are that treatments found in small randomized clinical trials do need confirmation and just the fact that it is a randomized clinical trial doesn’t necessarily mean that there does not need to be more confirmatory evidence. The take-home message from this trial is that in preventing contrast-induced nephropathy it’s really the simple things that should be emphasized and, at least at this point in time, there is no role for routine use of acetylcysteine.

– Brahmajee K. Nallamothu, MD

Associate Professor, Department of Internal Medicine,
University of Michigan, Ann Arbor

For more information:

Berwanger O. LBCT III: Abstract 21843. Presented at: American Heart Association Scientific Sessions 2010; Nov. 13-17, 2010; Chicago.

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