Acetylcysteine for Contrast-Induced Nephropathy Trial - ACT


The goal of the trial was to evaluate treatment with acetylcysteine compared with placebo among patients at risk for contrast-induced nephropathy (CIN) undergoing an angiographic procedure.


Acetylcysteine will be superior at preventing CIN.

Study Design

  • Blinded
  • Placebo Controlled
  • Randomized
  • Parallel
  • Stratified

Patient Populations:

  • Patients with at least one risk factor for CIN undergoing an angiographic procedure (coronary or peripheral diagnostic or interventional procedure)
  • Risk factors for CIN defined as age >70 years, chronic renal failure (creatinine >1.5 mg/dl), diabetes, heart failure, left ventricular ejection fraction <45%, or hypotension

    Number of enrollees: 2,308
    Duration of follow-up: 30 days
    Mean patient age: 68 years
    Percentage female: 38%


  • Dialysis
  • ST-elevation myocardial infarction
  • Pregnant or breastfeeding women
  • Women <45 years of age without use of contraceptive method

Primary Endpoints:

  • CIN defined as 25% increase in creatinine from baseline, 48 to 96 hours after angiography

Secondary Endpoints:

  • Total mortality
  • Cardiovascular mortality
  • Dialysis
  • More than 0.5 mg/dl increase in serum creatinine between 48 and 96 hours
  • Side effects

Drug/Procedures Used:

Patients in Brazil at risk for CIN were randomized to acetylcysteine 1200 mg twice daily for 2 days (n = 1,172) versus placebo (n = 1,136). Patients received two doses of study medication prior to the procedure and two doses after the procedure. Patients in both groups underwent prehydration with normal saline or bicarbonate.

Principal Findings:

Overall, 2,308 patients were randomized. In the acetylcysteine group, the mean age was 68 years, 51% were age >70 years, 38% were women, 15% had chronic renal failure, 61% had diabetes, 66% underwent diagnostic coronary angiography, 30% underwent percutaneous coronary intervention, and the median volume of contrast delivered was 100 cc. The mean estimated glomerular filtration rate was 69 ml/min. The median duration of hydration was 6 hours before and 6 hours after the procedure.

The primary outcome, CIN, occurred in 12.7% of the acetylcysteine group versus 12.7% of the placebo group (p = 0.97). The result was the same among patients with more advanced renal dysfunction. Doubling of serum creatinine occurred in 1.1% versus 1.5% (p = 0.41), elevation of serum creatinine ≥0.5 mg/dl occurred in 3.9% versus 3.8% (p = 0.85), total mortality occurred in 2.0% versus 2.1% (p = 0.92), cardiovascular mortality occurred in 1.5% versus 1.6% (p = 0.97), need for dialysis occurred in 0.3% versus 0.3% (p = 0.86), and serious adverse events occurred in 1.3% versus 2.2% (p = 0.09), respectively, for acetylcysteine versus placebo.


Among patients at risk for CIN undergoing an angiographic procedure, the use of acetylcysteine was not effective at preventing CIN or important clinical outcomes. This represents the largest and most definitive trial on the topic. Adequate prehydration remains the principal measure to prevent CIN. Although prevention of CIN remains a priority, the incidence of this complication was lower in this trial than anticipated. It was also reassuring that mortality and dialysis occurred at a low frequency.


ACT Investigators. Acetylcysteine for Prevention of Renal Outcomes in Patients Undergoing Coronary and Peripheral Vascular Angiography: Main Results From the Randomized Acetylcysteine for Contrast-Induced Nephropathy Trial (ACT). Circulation 2011;Aug 22:[Epub ahead of print].

Presented by Dr. Otavio Berwanger at the American Heart Association Scientific Sessions, Chicago, IL, November 16, 2010.

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Acute Heart Failure, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Kidney Function Tests, Kidney Failure, Chronic, Hypotension, Risk Factors, Creatinine, Percutaneous Coronary Intervention, Renal Dialysis, Kidney Diseases, Bicarbonates, Coronary Angiography, Brazil, Heart Failure, Stroke Volume, Glomerular Filtration Rate, Diabetes Mellitus

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