Contrast-induced acute kidney injury (CI-AKI) predicts unfavorable outcomes. The use of the RenalGuard™® system, to create high urine output and fluid balancing, may be beneficial in preventing CI-AKI. The REMEDIAL II trial is a randomized, multicenter, investigator-driven trial addressing the prevention of CI-AKI in high risk patients. Consecutive patients with an estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m2 and/or a risk score ≥11 were randomly assigned to 1) sodium bicarbonate solution and N-acetylcysteine (NAC) (Control group) or 2) the RenalGuard therapy, that is, hydration with saline and NAC controlled by the RenalGuard System and furosemide (RenalGuard group). CI-AKI (defined as an increase of ≥0.3 mg/dL in the serum creatinine concentration at 48 hours after the procedure) occurred in 16/146 patients in the RenalGuard group (11%) and in 30/146 patients in the Control group (20.5%) (P=0.025; OR=0.47; 95% CI=0.24-0.92). Absolute changes in CyC at 24 hours (0.02±0.32 versus -0.08±0.26; P=0.002) and at 48 hours (0.12±0.42 versus -0.03±0.31; P=0.001), as well as the rate of in-hospital dialysis (4.1% versus 0.7%; P=0.056) were higher in the Control group. In conclusion, the RenalGuard therapy seems to be a promising new approach in preventing CI-AKI in high risk patients.