Choice of Contrast Medium in Patients With Impaired Renal Function Undergoing Percutaneous Coronary Intervention

Background-No clinical trial has yet focused on contrast-mediated nephrotoxicity in patients with chronic renal failure exclusively undergoing percutaneous coronary intervention (PCI). Therefore, the aim of this study was to compare the effect of contemporary contrast media on nephrotoxicity in this high-risk patient population. Methods and Results-This prospective, randomized, double-blind, comparative clinical trial randomly selected 939 patients with chronic renal failure undergoing coronary angiography with potential PCI to receive either the iso-osmolar contrast medium iodixanol or the low-osmolar contrast medium iomeprol. Of those 939 patients, 615 received diagnostic angiography only and were not included in the primary study analysis, but were followed up in a registry. Three hundred twenty-four patients underwent PCI, of which one-half received iodixanol or iomeprol, respectively, and were included in the primary study analysis. The primary end point was the peak increase in S-creatinine during hospitalization for PCI. Maximum increase in S-creatinine after PCI was lower than expected and thus impaired the power of the study. It was not significantly different between the 2 contrast groups (0.19 +/- 0.40 mg/dL for iodixanol and 0.21 +/- 0.34 mg/dL for iomeprol; P = 0.53). Albeit contrast media-induced nephropathy rates were lower with iodixanol (22.2% compared with 27.8% for iomeprol), this difference was not statistically different (P = 0.25). Subgroup analysis suggested a favorable outcome regarding nephrotoxicity in patients who received higher contrast volumes (> 340 mL) in the iodixanol group (P(interaction) = 0.016). Conclusions-Routine use of iso-osmolar contrast medium is not associated with a significant reduction of nephrotoxicity compared with low-osmolar contrast medium in patients with chronic renal failure undergoing PCI. However, a positive effect was seen in the iso-osmolar contrast group for patients receiving high amounts of contrast medium, which awaits confirmation of a specifically designed randomized clinical trial.