Dearth of Evidence for Contrast-Induced Nephropathy

Background: The American College of Radiology (ACR) and National Kidney Foundation (NKF) define contrast-induced nephropathy as acute kidney injury (AKI) occurring within 48 hours of iodinated contrast media (ICM) exposure without additional nephrotoxic factors. Objective: To describe the evidence associating ICM with AKI. Design: Narrative review. Discussion: Available evidence suggests ICM exposure may correlate with—but not cause—AKI. Evidence linking ICM with AKI comes largely from uncontrolled trials. Studies have not shown elevation in biomarkers of renal injury following ICM exposure. Additionally, the rapid recovery and low rates of progression to chronic kidney disease (CKD) or dialysis after contrast-associated AKI perhaps indicate that creatinine elevation occurs via some mechanism other than true nephron injury. Large studies have shown that hospitalized patients have a significant risk for developing AKI independent of ICM exposure. A study of stroke patients showed a lo more...