Contrast-induced nephropathy in patients undergoing computed tomography (CONNECT) - A clinical problem in daily practice? A multicenter observational study

Background: Although several studies have examined contrast-induced nephropathy (CIN) following computed tomography (CT) procedures under closely controlled clinical trial conditions, less is known about the incidence of CIN (or its key predictive factors) in a "real world" clinical setting. Purpose: A multicenter, observational registry study was undertaken in Italian hospital radiology departments to retrospectively assess the incidence of CIN in at-risk patients undergoing iodixanol-enhanced CT procedures. Material and Methods: Each department used center-specific (nonstandardized) CT protocols. Data were available from 493 at-risk patients; most (76.4%) had 1 risk factor for CIN, 19.8% had 2, and 3.4% had 3. In all, 169 patients (34.3%) had reduced renal function (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73m²). Prophylactic volume expansion was not used in 70.6% of the study population. Results: The overall incidence of CIN (defined as a ≥44.2 μmol/l [0.5 mg/dl] increase in serum creatinine from baseline 72 h postprocedure) was 2.6%; in the subpopulation of patients with renal impairment (with or without other risk factors), CIN incidence was 4.7%. Multivariate analysis identified renal insufficiency as the only risk factor predictive of CIN (relative risk, 3.850; 95% confidence interval, 1.20012.348; P0.023). Conclusion: In the clinical setting of hospital CT radiology practice, where guideline-recommended strategies for CIN prevention may not be consistently followed, use of the iso-osmolar agent iodixanol appears to be associated with a low incidence of CIN in at-risk patients.