Sasan Partovi

Our paper commented on a large retrospective observational study by Myung and colleagues investigating postcontrast acute kidney injury in patients with stroke undergoing CTA followed by cerebral angiography.¹ In this study, the authors found that 9.5% (57 out of 601 patients) of included patients developed postcontrast acute kidney injury. From the patients affected by postcontrast acute kidney injury, only 8.7% (5 out of 57 patients) required some form of renal replacement therapy (which was 0.8% of all patients included in the study). In these 5 patients, kidney function recovered within less than 1 week. The same was holding true for the other patients developing postcontrast acute kidney injury, demonstrating renal function recovery within a short time period.

The importance of this paper lies not only in the excellent examination of postcontrast acute kidney injury, but more importantly in the association of the disease with the requirement for renal replacement therapy and the likelihood of recovery as a crucial clinical outcome parameter.

The study essentially suggests that CTA followed by angiography (in this case in the stroke population) can be pursued safely and that postcontrast acute kidney injury seems to have minor clinical consequences. In other words, the benefits of treating the acute disease far outweigh the risks associated with postcontrast acute kidney injury.

In clinical practice with patients requiring urgent and/or emergent angiography, the topic of postcontrast acute kidney injury still seems to be given significant weight, and this can lead to a delay of imaging with CTA and subsequent management of the patient. The paper by Myung and colleagues supports the concept of proceeding with CTA followed by angiography treatment if indicated even in cases of higher risk of postcontrast acute kidney injury in the chronic kidney disease population. In most patients developing postcontrast acute kidney injury, it is a temporary phenomenon and renal function will eventually recover.

The paper by Myung and colleagues focuses on the ischemic stroke population, but there is a possibility that the conclusions of the study may be extrapolated to other disease processes. For example, patients with gastrointestinal bleeding often require a CTA to localize the hemorrhagic source followed by angiography to embolize the arterial bleeding culprit. Both studies performed subsequently are associated with a significant contrast load. Further studies are warranted in the gastrointestinal bleeding and other patient populations to confirm the relatively limited clinical relevance of postcontrast acute kidney injury relative to the acute disease process as shown by Myung and colleagues in the ischemic stroke population.

Reference

1. Myung JW, Kim JH, Cho JH, et al. Contrast-induced acute kidney injury in radiologic management of acute ischemic stroke in the emergency setting. AJNR Am J Neuroradiol 2020;41:632–36

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