BACKGROUND. Despite the potential benefits of percutaneous procedures for the assessment and treatment of coronary artery disease, these interventions require the use of iodine contrast, which might lead to contrast-induced nephropathy (CIN) and increased risk of dialysis and major adverse cardiac events (MACE). Aims. We sought to compare two different iodine contrasts (low vs. iso-osmolar) for the prevention of CIN among high-risk patients. METHODS. This is a single-center, randomized (1:1) trial comparing consecutive patients at high risk for CIN referred to percutaneous coronary diagnostic and/or therapeutic procedures with low (ioxaglate) vs iso-osmolarity (iodixanol) iodine contrast.

High risk was defined by the presence of at least one of the following conditions:

age >70 years, diabetes mellitus, non-dialytic chronic kidney disease, chronic heart failure, cardiogenic shock, and acute coronary syndrome (ACS). The primary endpoint was the occurrence of CIN, defined as a >25% relative increase and/or >0.5 mg/dL absolute increase in creatinine (Cr) levels compared with baseline between the 2nd and 5th day after contrast media administration. RESULTS. A total of 2268 patients were enrolled. Mean age was 67 years. Diabetes mellitus (53%), non-dialytic chronic kidney disease (31%), and ACS (39%) were highly prevalent. The mean volume of contrast media was 89 ml ± 48.6. CIN occurred in 15% of all patients, with no significant difference regarding the type of contrast used (iso = 15.2% vs low = 15.1%, P>.99). Differences were not observed in specific subgroups such as diabetics, elderly, and ACS patients. At 30-day follow-up, 13 patients in the iso-osmolarity group and 11 in low-osmolarity group required dialysis (P=.8). There were 37 (3.3%) deaths in the iso-osmolarity cohort vs 29 (2.6%) in the low-osmolarity group (P=.4). CONCLUSION. Among patients at high risk for CIN, the incidence of this complication was 15%, and independent of the use of low- or iso-osmolar contrast.