RenalGuard ineffective in preventing high-risk contrast-induced nephropathy

France: According to a recent study in the Journal of the American College of Cardiology, RenalGuard, a medical device that delivers real-time isotonic intravenous (IV) hydration paired with furosemide-induced diuresis, does not reduce the risk for contrast-induced nephropathy (CIN) in high-risk patients undergoing complex cardiovascular interventions. 

Following cardiovascular operations involving contrast media, contrast-induced nephropathy (CIN) can develop, which is linked to higher morbidity and death. In prior randomized controlled studies, the effectiveness of RenalGuard, a closed-loop device that matches intravenous hydration with diuretic-induced diuresis, has been equivocal.

In the STRENGTH (Study Evaluating the Use of RenalGuard to Protect Patients at High Risk of AKI) study, researchers looked at whether RenalGuard is more effective than traditional IV hydration in preventing CIN in patients with moderate to severe chronic kidney disease (estimated glomerular filtration rate [eGFR] 15-40 mL/min/1.73 m2) who are undergoing complicated percutaneous coronary, peripheral, and structural interventions with anticipated contrast media doses of at least 3 times the eGFR.

A total of 259 patients with moderate to severe chronic kidney disease (estimated glomerular filtration rate: 15–40 mL/min/m2) who needed a complex coronary, structural, or peripheral procedure with an anticipated contrast injection of at least three times the estimated glomerular filtration rate were included in the multicenter, international, open-label, postmarket, prospective, randomized (1:1) study known as STRENGTH, which was overseen by the Cardiovascular European Research Center (Massy, According to current recommendations, patients were randomized to receive either RenalGuard or IV saline hydration.

Key findings of the study:

• There was no statistically significant difference between the primary endpoint occurring in 17 (15.9%) of the 107 patients in the RenalGuard group and 15 (13.9%) of the 110 patients in the control group.
• The researchers found no statistically significant differences in the secondary endpoints, which included serious adverse cardiovascular and cerebrovascular events, change in serum creatinine and eGFR values at 12 months, and percentage of patients on chronic or temporary hemodialysis at 12 months, between the study arms or the individual components of the CIN definition.
• The average contrast volume given to the RenalGuard and control groups was comparable (116 mL and 104 mL, respectively).

The authors affirmed that their results diverge from those of earlier randomized controlled studies, which discovered that RenalGuard dramatically decreased the rate of CIN in patients having cardiovascular operations.

They came to the conclusion that using the RenalGuard system with furosemide-induced high urine output and matched hydration did not lower the risk of CIN and serious complications at 12 months compared to using traditional intravenous hydration in high-risk patients undergoing complex cardiovascular interventions in experienced centers.

REFERENCE

Mauler-Wittwer S, Sievert H, Ioppolo A, et al. Study Evaluating the Use of RenalGuard to Protect Patients at High Risk of AKI. J Am Coll Cardiol Intv. 2022 Aug, 15 (16) 1639-1648.https://doi.org/10.1016/j.jcin.2022.05.036