Abstract 4843: Furosemide-induced Diuresis With Matched Replacement of Intravascular Volume Compared to Standard Hydration for Contrast-induced Nephropathy Prevention: The Mythos Trial
Hypothesis. We investigated the effect of a new preventive strategy strategy for contrast-induced nephropathy (CIN) based on a dedicated device (RenalGuard; PLC Medical System Inc., USA). The system is capable of delivering i.v. saline solution to a patient in an amount matched to the volume of urine produced after an i.v. bolus of furosemide. The aim of the study was to evaluate if furosemide-induced high-volume diuresis with concurrent maintenance of intravascular volume may prevent CIN.
Methods. To date, 63 chronic kidney disease (CKD) patients (eGFR<60 ml/min/1.73 m2) undergoing percutaneous coronary interventions (PCI) were enrolled in the MYTHOS trial. They were randomized to matched hydration (RenalGuard group, n=30) or to i.v. isotonic saline hydration (control group; n=33) at a rate of 1 ml/kg/hour for 12 hours before and after PCI. Matched fluid replacement was started approximately 90 minutes pre-PCI, maintained during catheterization, and for up to 4 hours afterwards. Patients were given an initial i.v. bolus of 250 ml of normal saline over 30 minutes and then an i.v. bolus of furosemide (0.5 mg/kg). The RenalGuard measures the patient’s urine volume and then automatically adjusts the infusion pump rate to precisely replace the measured urine output in real time. When a >300 ml/hour urine output rate was obtained, patients underwent PCI. CIN was defined as a ≥0.5 mg/dl or ≥25% rise in serum creatinine over baseline.
Results. Overall, the mean eGFR was 40±9 ml/min/1.73 m2. The mean contrast volume was 190±92 ml in RenalGuard group and 212±118 ml in controls (P=0.4). In RenalGuard group, urine output ranged from 319 to 1788 ml/hr (mean 830±322 ml/hr). There were no serious device-or therapy-related complications, including clinically significant electrolyte changes (asymptomatic ipokalemia was corrected in 1 case). CIN occurred in no patient (0%) of the RenalGuard group and in 5 (15%) controls (P=0.03). Two controls (6%) required temporary renal replacement therapy.
Conclusions. These preliminary results indicate that furosemide-induced high urine output with maintenance of intravascular volume through matched hydration can be safely obtained with the RenalGuard system and may reduce the risk of CIN in CKD patients undergoing PCI.