NEW YORK (Reuters Health) - Only two strategies offer some effectiveness in preventing contrast-induced nephropathy (CIN), according to a systematic review and meta-analysis of 86 randomized, controlled trials.
Those are use of N-acetylcysteine (NAc) in patients receiving low-osmolar contrast media (LOCM), and statins plus NAc.
The reported incidence of CIN, defined as an increase in serum creatinine levels >25% or 44.2 mmol/L (0.5 mg/dL) within three days of IV administration of contrast media, ranges from 7% to 11% and adds an average $10,345 to a CIN-related hospital stay. There is no clear consensus about the most effective intervention to prevent or reduce CIN.
Dr. Rathan M. Subramaniam and colleagues from Johns Hopkins University in Baltimore compared five strategies for preventing CIN in their systematic review and meta-analysis: IV NAc plus saline versus IV saline alone; IV sodium bicarbonate versus IV saline; NAc plus IV saline versus IV sodium bicarbonate; statins with or without NAc versus IV saline; and ascorbic acid versus NAc or IV saline.
In the NAc studies, all of which had low strength of evidence, NAc had a clinically important benefit in reducing CIN risk only when LOCM were used.
Low-dose NAc had a borderline clinically important effect on preventing CIN, whereas high-dose NAc had a statistically significant (but clinically unimportant) effect on reducing CIN risk (with low strength of evidence).
Similarly, statins when added to NAc showed a clinically important reduction in CIN risk, although with low strength of evidence.
IV sodium bicarbonate (versus IV saline), NAc (versus IV sodium bicarbonate), and ascorbic acid (versus other strategies) showed no statistically significant, clinically important benefit in reducing CIN risk, according to the report onine February 1 in Annals of Internal Medicine online.
"The studies span over two decades, and there may have been changes in the practice of CIN prevention, such as increased screening, variation in definition of acute kidney injury, and variation in hydration, over time," the researchers noted. "Such changes could contribute to differences in outcomes."
"This comprehensive review highlights the generally low strength of evidence on interventions for preventing CIN while indicating that the greatest reduction in CIN risk has been achieved with low-dose N-acetylcysteine in patients receiving LOCM or with statins plus N-acetylcysteine," they concluded.
In a related article, the group from Johns Hopkins University found no differences in CIN risk among the different types of LOCM. Iodixanol had a slightly lower risk of CIN than LOCM did, but the difference was not clinically important.
Dr. Guillaume Mahe from CHU de Rennes, Rennes, France recently reviewed remote ischemic preconditioning, another proposed method for preventing CIN (http://bit.ly/23EU40a). He told Reuters Health by email, "It seems of interest to use N-acetylcysteine, which is a low cost drug. Statins might be also a good option. This is another interesting effect of the statins, which is unknown by most physicians."
Even more important, Dr. Mahe said, is to "be sure that the patients need a computed tomography angiography with contrast media."
He expressed surprise that the authors did not assess the role of remote ischemic preconditioning in their review.
Dr. Subramaniam did not respond to a request for comments. The Agency for Healthcare Research and Quality funded both studies.