REnal insufficiency following contrast MEDIA administration II triaL - REMEDIAL II


The goal of the trial was to evaluate hydration with an automated hydration system (RenalGuard system) compared with sodium bicarbonate among patients at elevated risk for contrast-induced nephropathy.


Automated hydration will prevent contrast-induced nephropathy.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • Patients at least 18 years of age at elevated risk of contrast-induced nephropathy (contrast score ≥11 and/or eGFR <30 ml/min/1.73 m2) undergoing contrast administration

    Number of screened applicants: 806
    Number of enrollees: 294
    Duration of follow-up: 30 days
    Mean patient age: 76 years
    Percentage female: 39%
    Ejection fraction: 46%


  • Primary PCI or acute myocardial infarction
  • Rescue PCI
  • Pregnancy
  • Recent contrast exposure
  • End-stage renal failure
  • Multiple myeloma
  • Pulmonary edema
  • Administration of theophylline, dopamine, mannitol, fenoldopam, or sodium bicarbonate

Primary Endpoints:

  • Serum creatinine increase >0.3 mg/dl at 48 hours

Secondary Endpoints:

  • Serum creatinine increase ≥25% and ≥0.5 mg/dl at 48 hours
  • Change in serum cystatin concentration at 24 and 48 hours after contrast exposure
  • Acute renal failure requiring dialysis
  • In-hospital and 30-day major adverse events (defined as death, dialysis, or pulmonary edema)
  • Change in serum and urine NGAL concentration at 2, 6, 12, 24, and 48 hours after contrast exposure

Drug/Procedures Used:

  • Patients at elevated risk of contrast nephropathy were randomized to an automated hydration system (n = 147) versus sodium bicarbonate hydration (n = 147).
  • Patients in the sodium bicarbonate group received sodium bicarbonate at 3 ml/kg intravenously 1 hour before and 1 ml/kg/h intravenously for 6 hours after the procedure.
  • Patients in the automated hydration group received normal saline and furosemide 0.25 mg/kg to achieve a urine flow of at least 300 ml/h prior to initiation of the procedure. This was a closed loop system, which required placement of a urinary catheter. The rate of fluid infusion was automatically titrated according to urine output.
  • Patients in both groups received periprocedural N-acetylcysteine.

Concomitant Medications:

At baseline, use of an angiotensin-converting enzyme inhibitor was 48%, angiotensin-receptor blocker 29%, calcium channel blocker 25%, beta-blocker 63%, and statin 74%

Principal Findings:

Overall, 294 patients were randomized. In the automated hydration group, the mean age was 76 years, 39% were women, 98% had hypertension, 69% had diabetes, mean body mass index was 28 kg/m2, mean blood pressure was 152/77 mm Hg, mean left ventricular ejection fraction was 46%, mean estimated glomerular filtration rate (eGFR) was 32 ml/min/1.73 m2, 73% had a contrast risk score of 11-15, and mean volume of contrast exposure was 135 ml.

Urine volume at 24 hours was greater in the automated hydration group compared with the bicarbonate group (p < 0.001).

The primary outcome, serum creatinine increase >0.3 mg/dl at 48 hours, occurred in 11% of the RenalGuard group versus 20.5% of the bicarbonate group (p = 0.025). Serum creatinine increase ≥0.5 mg/dl at 48 hours occurred in 6% versus 15% (p = 0.003), and major adverse events at 30 months occurred in 6.8% versus 9.6% (p = 0.52), respectively.


Among patients at high risk for contrast-induced nephropathy, hydration with an automated hydration system plus low-dose furosemide prevented serum creatinine increase more effectively post-procedure compared with sodium bicarbonate hydration. This system achieved high urine flow volume. Major adverse events (death, dialysis, or pulmonary edema) were nonsignificantly reduced in the automated hydration group. Automated hydration would be relatively contraindicated in patients with reduced left ventricular function or congestive heart failure.

Meta-analysis has shown that sodium bicarbonate hydration is more effective than normal saline hydration; however, that strategy has not eliminated contrast-induced nephropathy. Among the highest risk patients, an automated hydration system might be the preferred approach to prevent contrast-induced nephropathy. Further study is warranted.


Briguori C, Visconti G, Focaccio A, et al.; on behalf of the REMEDIAL II Investigators. Renal Insufficiency After Contrast Media Administration Trial II (REMEDIAL II): RenalGuard System in High-Risk Patients for Contrast-Induced Acute Kidney Injury. Circulation 2011;Aug 15:[Epub ahead of print].

Presented by Dr. Carlo Briguori at the ACC.11/i2 Summit, New Orleans, LA, April 4, 2011.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Statins, Acute Heart Failure, Hypertension

Keywords: Pulmonary Edema, Follow-Up Studies, Ventricular Function, Left, Blood Pressure, Sodium Bicarbonate, Creatinine, Furosemide, Urinary Catheters, Renal Dialysis, Body Mass Index, Bicarbonates, Heart Failure, Stroke Volume, Glomerular Filtration Rate, Hypertension, Diabetes Mellitus

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