Responses
Other responses
Jump to comment:
- Published on: 7 March 2019
- Published on: 7 March 2019How negative results can become positive ones
The authors of the metanalysis "Pharmacological interventions for the prevention of contrast-induced acute kidney injury in high-risk adult patients undergoing coronary angiography: a systematic review and meta-analysis of randomised controlled trials" conclude that "several drugs are renoprotective in patients with CKD [...] the evidence is strongest for NAC".
This conclusion is at odds with previous research and metanalyses. The same authors report 10 papers (over a total of 27) which show potentially harmful effects of NAC (OR >1). Furthermore, the paper they cite with the largest sample size (by Weisbord et al, n>2000) does not show any beneficial effect of NAC. Notwithstanding these data, the authors "recommend that NAC should be used when a high dose of contrast is anticipated". I believe the readers should be aware about the poor evidence supporting this conclusion.
NAC is a well-tolerated substance and, clearly, its use is unlikely to represent harm for patients (even though 1/3 of the studies reported by the authors would suggest that some negative effect might exist). Therefore, the main reason for its recommendation is its anxiolytic effect on physicians, who are convinced to use a "renoprotective" drug.Conflict of Interest:
None declared.