The potential adverse renal outcome among patients undergoing iodine-based contrast-enhanced computerized tomography (CT) has been questioned recently, given the caution undertaken in patients' selection, hydration protocols, and the low radiocontrast volume, used with advanced imaging equipment.
This study is a retrospective assessment of renal outcome in 12,580 hospitalized patients undergoing contrast-enhanced CT, compared with 754 patients subjected to gadolinium-based magnetic resonance imaging, with subsequent propensity matching for clinical characteristics and potential risk factors.
The risk of postcontrast acute kidney injury (PC-AKI) was found to be negligible as compared with patients undergoing enhanced magnetic resonance imaging studies, before and after propensity matching (8% vs 7.3% rate of AKI in the nonmatched iodine-based contrast agents [IBCAs] and gadolinium-based contrast agents [GBCAs], respectively, P = 0.3, and 7% in the matched IBCA group, P = 0.9), including comparisons among subgroups with well-defined risk factors such as chronic renal failure, diabetes, older age, and hypertension. However, lower systolic blood pressure before imaging was associated with higher risk to develop PC-AKI after IBCA administration but not with GBCA (for systolic blood pressure lower than 110 mm Hg, odds ratio for AKI after IBCA was 1.49; 95% confidence interval, 1.16–1.88, and after GBCA; odds ratio, 0.12; 95% confidence interval, 0.003–0.73).
With the current precautions undertaken, the real-life risk of PC-AKI among inpatients undergoing CT is insignificant. Possible reasons for the diverse impact of blood pressure on the propensity to develop acute kidney failure after iodine-based but not gadolinium-based enhancement imaging are discussed.
From the *Internal Medicine D, Rambam Health Care Campus;
†Institute of Endocrinology, Diabetes & Metabolism, Rambam Health Care Campus, Haifa;
‡Department of Medicine, Hadassah Hebrew University Hospital Mt. Scopus, Jerusalem; and
§The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Institute of Technology, Haifa, Israel.
Received for publication September 24, 2018; and accepted for publication, after revision, October 17, 2018.
Conflicts of interest and sources of funding: none declared.
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Correspondence to: Samuel N. Heyman, MD, Department of Medicine, Hadassah Hebrew University Hospital, Mt Scopus, PO Box 24035, Jerusalem 91240, Israel. E-mail: Heyman@cc.huji.ac.il.