Low incidence of nephrotoxicity following intravenous administration of iodinated contrast media: a prospective study

Objectives To estimate the incidence of contrast-induced acute kidney injury (CI-AKI) after intravenous (iv) iodinated contrast material (ICM) exposure. Methods This prospective cohort study included all consecutive patients who underwent radiological investigations using low-osmolar iopamidol 370 mg/ml in a regional hospital over a period of 36 months, without any exclusion criteria. The estimated glomerular filtration rate (eGFR) was evaluated using the MRDR equation before (2–10 days) and after (24–36 h) radiological investigations. CI-AKI was defined as a ≥ 25% decrease in eGFR from baseline. CI-AKI incidence was estimated using a binomial distribution. The association between CI-AKI and demographic and clinical characteristics was modeled using logistic regression. Results The study included 1541 patients with a median age of 68 (1st–3rd quartiles 58–76) years with various comorbidities, 30% of whom had pre-existing CKD. Patients affected by stage III or IV chronic kidney disease (CKD) received an infusion of 0.9% normal saline (1.0–1.5 ml/kg/h) before and after iso-osmolar iodixanol administration. CI-AKI was observed in 33 patients (2.1%, 95% CI 1.5–3.0). The logistic regression analysis showed that antibiotic and statin therapies were significantly associated with CI-AKI. The probability of developing CI-AKI decreased by 80% in patients taking statins (OR = 0.20, 95% CI 0.03; 0.68) and increased approximately three times in patients with antibiotic therapy compared with those who did not take statins and antibiotics (OR = 2.92, 95% CI 1.21; 6.36). Conclusions Our data suggest that low-osmolar iopamidol carries a low incidence of nephrotoxicity, even in subjects with various comorbid conditions or reduced renal function. Key Points • IV administration of ICM carries a low incidence of nephrotoxicity, which was transient in observed patients. • Statin therapy is negatively associated with AKI in patients exposed to ICM. • Pre-existing impairment of renal function is not associated with AKI in patients exposed to ICM.