Is Sodium Bicarbonate or N-Acetyl-Cysteine Effective in Preventing Contrast-Induced Nephropathy?

In a recent study published in the New England Journal of Medicine, it was found that amongst patients undergoing angiography, sodium bicarbonate is not better than sodium chloride  and neither is acetylcysteine better than oral placebo in the prevention of a composite outcome of death, need for dialysis, or persistent kidney injury. The treatment was also ineffective in reducing the risk of contrast-associated acute kidney injury.

Contrast associated nephropathy has been a serious clinical problem and has numerous health risks such as acute kidney injury, chronic kidney disease, and death. Oral acetylcysteine and IV sodium bicarbonate have been used to prevent this risk despite a lack of high-quality evidence of benefit. The PRESERVE trial investigated the efficacy of these interventions.

Weisbord et al used a 2-by-2 factorial design to randomly assign 5,177 patients at high risk for renal complications who were scheduled for angiography. The first randomized interventional treatment compared intravenous sodium bicarbonate with isotonic sodium chloride, while the second tested treatment compared oral N-acetylcysteine with placebo.

A total of 4,993 patients were included in the modified intention-to-treat analysis for the interpretation of the primary study results. The primary endpoint was the occurrence of a composite of death, need for dialysis or persistent increase ≥50% of serum creatinine at 90 days after angiography. There was no difference in the primary outcome in the sodium bicarbonate group relative to the sodium chloride group or in the acetylcysteine group relative to the placebo group. The study was terminated after an interim analysis.

The PRESERVE trial provides compelling evidence of a lack of benefit for treatment with sodium bicarbonate over sodium chloride or N-acetylcysteine over oral placebo for the prevention of death or kidney injury in patients with impaired renal function undergoing coronary or non-coronary angiography.

The study also highlights the fact that volume and type of intravenous contrast may differ between angiography and diagnostic imaging, thereby limiting generalizability. The creatinine measurements were not obtained between 3-5 days and 90-104 days, so it is possible that there was a transient creatinine rise within this period that was undetected.