Imaging not associated with increased AKI risk in stroke patients, study finds

The meta-analysis compared rates of acute kidney injury (AKI) among patients (including some with chronic kidney disease) who underwent computed tomographic (CT) angiography, CT perfusion, or noncontrast CT.

Computed tomographic angiography (CTA) and computed tomographic perfusion (CTP) were not associated with increased risk for acute kidney injury (AKI) in patients with stroke, even in cases of known chronic kidney disease, a new study has found.

Researchers performed a systematic review and meta-analysis to determine whether CTA/CTP led to increased AKI risk in patients with stroke. Studies published through December 2016 were included if they involved patients having imaging for acute ischemic stroke, had at least 50 patients in each treatment group for case-control studies or 50 patients in the CTA/CTP group for single-arm studies, and reported separate outcomes for patients having CTA/CTP and those having noncontrast CT. Primary outcomes were odds of AKI in patients receiving CTA/CTP compared with noncontrast CT, overall rate of AKI and hemodialysis in patients with acute ischemic stroke who had CTA/CTP, and odds of AKI associated with CTA/CTP in patients with and without chronic kidney disease. The study results were published online June 5 by Stroke.

A total of 14 studies were included in the systematic review and meta-analysis, six of which were case-control studies and eight of which were single-arm studies. The studies included 5,727 patients undergoing CTA/CTP and 981 patients undergoing noncontrast CT. AKI was most commonly defined as a greater than 25% increase in creatinine level. In the case-control studies, incidence of AKI was significantly lower among patients receiving CTA/CTP versus patients receiving noncontrast CT (odds ratio, 0.47; 95% CI, 0.33 to 0.68; P<0.01). The researchers adjusted for baseline creatinine level and found no difference in AKI rates between groups (odds ratio, 0.34; 95% CI, 0.10 to 1.21). Among patients receiving CTA/CTP, the overall rate of AKI was 3% and the overall rate of hemodialysis was 0.07%. AKI rates did not differ in CTA/CTP patients with chronic kidney disease and CTA/CTP patients without chronic kidney disease (odds ratio, 0.63; 95% CI, 0.34 to 1.12).

The researchers noted that the evidence they analyzed was not from randomized controlled trials and that definitions of AKI and amount and type of contrast dye administered differed between studies, calling the certainty in their evidence low. However, they concluded that their results indicate a lack of association between contrast administration for CTA/CTP and risk for AKI in patients with acute ischemic stroke. “These findings suggest that delays in imaging and care because of absent or elevated creatinine values are not acceptable,” the authors wrote. “Concern about AKI should not deter physicians from pursuing their optimal imaging strategy for the management of patients with [acute ischemic stroke].” They called for future randomized controlled trials to confirm their results.