Acute Kidney Injury After Intravenous Versus Intra-Arterial Contrast Material Administration in a Paired Cohort

Objectives: The aim of this study was to determine whether intra-arterial administration of contrast material is associated with a higher risk of acute kidney injury (AKI) compared with that of intravenous (IV) administration in a cohort of patients that received both routes of administration. Materials and Methods: All patients who received both a contrast-enhanced computed tomography (CT) and a diagnostic or interventional cardiac catheterization between 2000 and 2014 were identified. Patients who lacked sufficient preprocedure and postprocedure serum creatinine results, who were on preexisting renal dialysis, or who underwent additional contrast-enhanced procedures within 7 days of either procedure were excluded. The rate of AKI (serum creatinine >= 0.3 mg/dL or 50% above baseline) was compared after CT scan and cardiac catheterization using McNemar test. Results: A total of 1969 patients met all study inclusion criteria. The rate of AKI after CT scan was similar to the rate after catheterization when examining all patients (9.9% CT vs 11% catheterization, P = 0.12). A similar rate of AKI after both procedures was observed regardless of procedure order, catheterization type, and patient baseline estimated glomerular filtration rate. Conclusions: Intra-arterial administration of contrast material during cardiac catheterization had a similar risk of AKI as compared with that of CT scanning involving IV administration in a cohort of patients who underwent both procedures. These findings suggest that previously reported much higher rates of AKI after cardiac catheterization compared with that of IV contrast administration reflect higher baseline clinical risk factors for AKI in the former cohort compared with that in the latter.