Abstract WP69: Computed Tomography Perfusion Imaging in Evaluation of Patients With Acute Stroke is Not Associated With Increased Risk of Acute Kidney Injury

Introduction: Mechanical thrombectomy has become standard of care in acute ischemic stroke with proximal arterial occlusion. For patients 6-24 hours from last known well, computed tomography perfusion (CTP) is now frequently used for assessment of endovascular therapy (EVT) eligibility. CTP requires an increased contrast load compared to computed tomographic angiography (CTA). Hypothesis: In patient assessment for EVT, CTA/CTP is not associated with higher incidence of acute kidney injury (AKI) compared to CTA alone. Methods: We reviewed data from consecutive acute stroke alerts at our institution from January-July 2018, and recorded baseline serum creatinine and creatinine at 24, 48, and 72 hours post-alert. AKI was defined by an increase in serum creatinine of 0.3, or more than a 1.5 fold increase in baseline creatinine, according to the Acute Kidney Injury Network definition. We compared patients receiving CTA/CTP versus CTA alone using independent samples t-test, including variables of age, NIHSS, baseline creatinine, and creatinine at 24, 48, and 72 hours. Chi-square testing was performed to compare incidence of AKI between groups. A binary logistic regression model was performed including covariates of age, sex, location of alert (emergency room or inpatient), NIHSS, baseline creatinine and imaging group. Significance was defined as p < 0.05 for all tests. Results: Analysis included 285 patients: 210 receiving CTA alone, and 75 receiving CTA/CTP. Incidence of AKI was 4.7% in the CTA alone group versus 4% in the CTA/CTP group (χ2=0.74, p=0.786). The two groups did not differ with regard to age, NIHSS, or serum creatinine at any time point. In the binary logistic regression model, addition of CTP to CTA did not increase the odds ratio of developing AKI (OR 1.076 [95% CI 0.276-4.193]; p=0.916). Conclusions: In acute stroke assessment for EVT eligibility, the addition of CTP to CTA did not increase rates of AKI. While this retrospective analysis includes the possibility of selection bias, the two groups were similar in baseline characteristics including kidney function. These results provide Level II, Class B evidence supporting the safety of CTP in patient selection for EVT and may inform future AHA/ASA guidelines for management of acute ischemic stroke.