Using propensity-score matching, two groups of about 10,000 patients each were created from a large database; these groups were virtually identical in clinical characteristics, except that one group had undergone contrast-enhanced CT and the other had undergone unenhanced CT. The 30-day incidences of dialysis (≈0.2%) and mortality (≈8%) after CT scanning were nearly identical in the two groups. Receiving contrast was not associated with higher rates of dialysis or death among patients whose serum creatinine levels before CT scanning were >2.0 mg/dL or among patients with other high-risk conditions (e.g., diabetes, heart failure).
Although this was a retrospective study which has its inherent limitations, it did involve a large number of patients with risk factors for contrast-induced nephropathy (creatinine >2 mg/dL, CHF, and diabetes). The study did not show an increased risk of either death or need for dialysis with the receipt of IV contrast.
This warrants a true large RCT to verify these results.