Renal Insufficiency After Contrast Media Administration Trial II (REMEDIAL II): RenalGuard System in High-Risk Patients for Contrast-Induced Acute Kidney Injury

Study Questions:

What is the safety and efficacy of the RenalGuard system for prevention of contrast-induced nephropathy (CIN)?


The authors performed a randomized evaluation of the RenalGuard system in 294 high-risk patients undergoing coronary or peripheral angiography/intervention. RenalGuard is a closed loop system that helps achieve high urine output while balancing urine output with venous infusion. Patients with an estimated glomerular filtration rate ≤30 ml or a CIN risk score ≥11 were randomly assigned to sodium bicarbonate solution and N-acetylcysteine or hydration with saline and N-acetylcysteine controlled by the RenalGuard System and furosemide (RenalGuard group). The primary endpoint was an increase in serum creatinine of ≥0.3 mg/dl at 48 hours after the procedure. The secondary endpoints included serum cystatin C kinetics and need for in-hospital dialysis.


Patients randomized to RenalGuard had a lower incidence of CIN (11% vs. 20.5%; odds ratio, 0.47; 95% confidence interval, 0.24-0.92). There was a similar reduction in need for in-hospital dialysis (4.1% vs. 0.7%; p = 0.056). A significantly greater increase in the serum cystatin C was seen in patients in the control arm compared with those in the RenalGuard arm. Three patients in the RenalGuard arm and one in the control arm developed pulmonary edema.


The authors concluded that RenalGuard is an effective method for prevention of CIN.


CIN is a major complication associated with coronary and peripheral angiography/intervention. The only proven prophylactic strategies remain adequate hydration, minimization of contrast volume, and use of iso-osmolar or certain low-osmolar contrast media. This study suggests that forced diuresis is particularly efficacious at preventing CIN and may be a useful tool, especially in the highest-risk patients. There are number of agents that have demonstrated significant promise with respect to reduction in CIN in initial studies and yet have failed in definitive trials. Additional adequately powered studies are needed before this system can be recommended for routine clinical use.

Clinical Topics: Statins

Keywords: Contrast Media, Renal Dialysis, Incidence, Renal Insufficiency, Kidney Diseases, Acute Kidney Injury, Diuresis, Glomerular Filtration Rate, Kinetics, Furosemide

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