Contrast-Induced Nephropathy After Computed Tomography in Stable CKD Patients With Proper Prophylaxis: 8-Year Experience of Outpatient Prophylaxis Program

Conflicting data have been reported on the clinical significance of contrast-induced nephropathy after CT scan (CT-CIN). In addition, the epidemiologic characteristics and clinical outcomes of CT-CIN following proper prophylactic intervention remain elusive. We examined the incidence, risk factors, and outcomes of CT-CIN in stable chronic kidney disease (CKD) patients using data collected from our outpatient CT-CIN prophylaxis program conducted between 2007 and 2014. The program recruited patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) using an electronic health record-based pop-up alert system and provided an identical protocol of CIN prophylaxis to all patients. A total of 1666 subjects were included in this study, and 61 of the 1666 subjects (3.7%) developed CT-CIN. Multivariate analysis showed that baseline eGFR, diabetes mellitus, and low serum albumin were significant risk factors for CT-CIN. The generalized additive model analysis revealed a nonlinear relationship between the baseline eGFR and the risk of CT-CIN. In this analysis, the risk of CT-CIN began to increase below an eGFR threshold of 36.8 mL/min/1.73 m(2). To assess the outcomes of CT-CIN, patients with and without CT-CIN were compared after propensity score-based 1:2 matching. CT-CIN did not increase the mortality rate of patients. However, patients with CT-CIN were significantly more likely to start dialysis within 6 months of follow-up, but not after those initial 6 months. CT-CIN developed in only a small number of stable CKD patients who received proper prophylactic intervention, and the risk of CT-CIN was increased in patients with more advanced CKD. Despite the low incidence, CT-CIN conferred a non-negligible risk for the initiation of dialysis in the acute period, even after prophylaxis.