Contrast-Induced Acute Kidney Injury in Patients With Renal Dysfunction Undergoing a Coronary Procedure and Receiving Non-Ionic Low-Osmolar Versus Iso-Osmolar Contrast Media

Abstract

BackgroundAlthough the superiority of low-osmolar over high-osmolar contrast agents in prevention of contrast-induced acute kidney injury (CI-AKI) is generally accepted, the relative nephrotoxicity of iso-osmolar over low-osmolar agents has not yet clearly defined. We examined the incidence of CI-AKI according to the type of contrast agent used in a randomized study of ascorbic acid for CI-AKI prevention. MethodsA total of 222 patients with baseline serum creatinine≥1.2mg/dL who were undergoing a coronary procedure and who were randomized to receive ascorbic acid or placebo were evaluated. The iso-osmolar agent iodixanol was used in 144 patients, whereas low-osmolar non-ionic agents were used in 78 patients (iomeprol, n=40; iobitridol, n=30; iopentol, n=8). CI-AKI was defined by an absolute serum creatinine increase of ≥0.5mg/dL or a relative increase of ≥25% measured 2 to 5days after the procedure. ResultsThe groups of patients who received iso-osmolar and low-osmolar non-ionic agents were well balanced in terms of demographic, clinical, and procedural characteristics. The overall CI-AKI incidence was 14.6% for the iso-osmolar iodixanol versus 14.1% for the combined low-osmolar non-ionic agents (iomeprol, 10%; iobitridol, 10%; iopentol, 50%). For iodixanol, the incidence of CI-AKI was 7.4% for patients randomized to receive ascorbic acid and 21.6% for placebo (P=0.02). The corresponding incidences for the low-osmolar non-ionic agents were 9.1% and 20.6%, respectively (P=0.19). ConclusionsNo differences in CI-AKI incidence were apparent among patients receiving non-ionic iso-osmolar iodixanol and non-ionic low-osmolar contrast agents. The preventative effect of ascorbic acid was also similar.