Maria A. Jepperson MD, Presenter: Nothing to Disclose

Douglas Adolphson MD, Abstract Co-Author: Nothing to Disclose

William E. Haley MD, Abstract Co-Author: Nothing to Disclose

Julia Crook PhD, Abstract Co-Author: Nothing to Disclose

Alexander Parker PhD, Abstract Co-Author: Nothing to Disclose

Joseph George Cernigliaro MD, Abstract Co-Author: Nothing to Disclose

The primary purpose of this prospective, randomized, double blinded study was to compare iohexol to iodixanol with respect to subsequent incidence of contrast induced nephropathy (CIN) in an outpatient population with pre-existing renal disease.

Following IRB approval, 124 outpatients with a glomerular filtration rate (GFR) of 45.0-59.9 mL/min obtained within 48 hours of the CT examination were prospectively enrolled and 102 met inclusion criteria for the study and had a return visit. Exclusion criteria included: age < 18 years, CT with IV contrast in the previous 10 days, end stage kidney or liver disease (defined by being currently considered for renal or liver transplant), acute illness, inpatient/emergency room visit. Patients were randomly assigned to receive 100 mL of either iohexol (47 patients) or iodixanol (55 patients); GFR and creatinine was again obtained 48-96 hours after CT examination. CIN was defined as having a decrease in GFR ≥ 20% or an increase in creatinine ≥ 25%. Statistical analysis consisted of estimation of proportions and odds ratios along with confidence intervals. A priori we had considered that the study would provide preliminary evidence of non-inferiority for iohexol if the 90% confidence interval (CI) for the odds ratio (ioxol vs. iodixanol) was found to have upper limit less than 1.5.

The overall rate of CIN in the study population was 5.9% (6/102, 95% CI: ), including one patient (2.1%) in the iohexol arm (95% CI: 0.4-11.1%) and five patients (9.1%) in the iodixanol arm (95% CI: 4.0-19.6%). These results met our goal of providing evidence of non-inferiority of iohexol (OR=0.22, 90% CI: 0.04-1.36). All 6 patients who developed CIN had additional risk factors for acute kidney injury (history of cancer, chemotherapy, prior nephrectomy, surgery between the CT and follow-up lab work).

This study suggests that, in outpatients with mild preexisting renal disease, iohexol is likely not associated with a higher risk of CIN than iodixanol. The overall rate of CIN seen in our specific outpatient population of ~6% is lower than previously reported rates (based largely off of inpatient cohorts with variable comorbidities, risk factors and greater background fluctuation).

Iodixanol is much more expensive than iohexol; a change in protocol will have a significant impact on overall health care delivery cost savings.

Jepperson, M, Adolphson, D, Haley, W, Crook, J, Parker, A, Cernigliaro, J, Contrast-Induced Nephropathy in Outpatients with Pre-existing Renal Disease: A Randomized Comparison between Iohexol (Omnipaque) and Iodixanol (Visipaque).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045485.html