Intra-renal delivery of fenoldopam reduced risk of contrast-induced nephropathy in high-risk patients.
WASHINGTON, D.C.—Targeted renal therapy (TRT) involving intrarenal administration of fenoldopam is safe and feasible in patients undergoing angiographic procedures, even in patients at elevated risk of suffering from contrast-induced nephropathy (CIN).
CIN is the third leading cause of hospital-acquired acute kidney injury (AKI). It is associated with a longer length of hospital stay, increased healthcare costs, and higher rates of in-hospital and long-term morbidity and mortality.
Previous attempts to prevent reductions in glomerular filtration rate (GFR) due to iodinated contrast via IV vasodilator administration have been fairly limited due to systemic hypotension. Studies to date have shown that IV volume expansion can reduce CIN, but it has not reduced its incidence to an acceptable level, especially in high-risk patients.
At the Society of Interventional Radiology annual meeting here, researchers presented findings from the Be-RITe Registry, a multi-center, multi-disciplinary, post-marketing study evaluating the Benephit catheter (Flow-Medica, Inc, Fremont, Calif.).
Benephit is a bifurcated catheter that allows bilateral renal artery access and simultaneous therapeutic infusion. It is believed that TRT, which delivers therapeutic agents directly to the kidneys via the renal arteries, may offer a solution for CIN and other forms of AKI by allowing previously ineffective IV agents to be delivered locally to the renal vascular bed.
A total of 593 patients undergoing coronary (35%) or peripheral (54%) interventions or surgical procedures (11%) were included in this evaluation. In 323 of the 593 patients undergoing peripheral interventions involving 132 mL of iodinated contrast media, TRT with fenoldopam (median dose was 0.4 mcg/kg per min) was performed adjunctively via the Benephit catheter. Of these patients, 210 patients (mean age 75.5 years; 52% male) had diabetes and their mean baseline creatinine clearance was 35.8 mL/min per 1.73 m2. CIN was defined as a creatinine increase of 25% or greater or 0.5 mg/dL or greater within 48 hours.
Bilateral renal artery cannulation was successful in 96% of the 593 cases. The CIN rate in the 210 diabetic patients was 1.4% compared with a predicted rate of 27.2%. In addition, the longer TRT infusions (one hour or more) and higher intrarenal fenoldopam doses (0.4 mcg/kg per min or greater) were independently associated with reduced CIN risk in these patients.
“We now know that the patients who are at high risk for contrast-induced nephropathy can be protected,” said Bret Wiechmann, MD, chief of interventional radiology at North Florida Regional Medical Center in Gainesville. “This is a large population of patients that we have studied so that is powerful in and of itself. However, it is an observational study.”
The new findings, Dr. Wiechmann said, are reassuring and support the concept that TRT is particularly well suited for use in high-risk patients such as those with chronic renal insufficiency and diabetes undergoing peripheral angiography and interventions.
“This method shows a lot of promise for improving on the current CIN prophylaxis strategies,” Dr. Wiechmann told Renal & Urology News.
“We know that we can lower a patient’s risk through hydration. That has been a consistent finding. The problem is a lot of these patients have congestive heart failure and so you have to titrate patients very carefully and you have to admit patients overnight to hydrate them slowly. So, this approach [using TRT] may have many advantages.”