CARRESS-HF: Ultrafiltration Disappoints in Acute Heart Failure

November 07, 2012

LOS ANGELES — Ultrafiltration was associated with worsening renal function and more severe adverse events compared with optimum drug therapy in patients with acute decompensated heart failure in the CARRESS-HF trial [1].

The study was presented today at the American Heart Association 2012 Scientific Sessions and published simultaneously in the New England Journal of Medicine.

Reporting the trial, Dr Bradley Bart (Hennepin County Medical Center, Minneapolis, MN) concluded: "Ultrafiltration offers no advantage to stepped pharmacologic care in patients with acute decompensated heart failure, worsened renal function, and persistent congestion. Treatment of these patients remains a challenging clinical problem in need of better therapy."

Dr Bradley Bart

"A Terrific and Important Study"

Designated discussant Dr Milton Packer (UT Southwestern, Dallas, TX) described CARRESS-HF as "a terrific and important study" showing "no support for using ultrafiltration instead of diuretics in patients who are responsive to diuretics." But he still believes ultrafiltration has a place for patients who are unresponsive to diuretics.

Packer explained that the main goal in acute decompensated heart failure is to get fluid out of the patient, and this trial was addressing whether drug therapy or a mechanical device is the best way to do this. "Although results showed that the amount of fluid removed was comparable with the two approaches, what was surprising and very disconcerting was that that renal function worsened significantly with ultrafiltration. We don't know why this occurred or if it contributed to the increased incidence of serious adverse events, but the worsening of renal function is a real concern here," he said.

Dr Milton Packer

Packer noted that ultrafiltration is currently used in patients not responding to diuretics, and this practice is not addressed in this trial. "The question that is being looked at is whether the mechanical system of ultrafiltration would be better than diuretics in patients who are responsive to diuretics. If this had been shown to be true, we could have gone to mechanical systems much earlier on in the treatment process."

Optimal Diuretic Dosing Key

He said this question has been asked before--in the UNLOAD trial--which suggested that more fluid may be offloaded with ultrafiltration, but there was concern in that trial that the diuretic doses used were not optimal. "The CARRESS-HF trial is therefore very important, as it optimized diuretic therapy and showed that under these circumstances, there was no benefit and possible harm with the mechanical approach."

The CARRESS-HF trial involved 188 patients with acute decompensated heart failure with worsening renal failure who were randomized to stepped pharmacological care or ultrafiltration. The primary end point was change in serum creatinine and change in weight (reflecting fluid offload) at 96 hours.

Results showed that similar weight loss occurred in both groups (average about 12 pounds), but while there was little change in creatinine levels in the drug-treated group, there was a significant increase in creatinine in the ultrafiltration group. There was no difference between the two groups in death or hospitalization for heart failure, but there were more severe adverse events in the ultrafiltration group (72% vs 57%), mainly due to kidney failure, bleeding complications, and IV-catheter–related complications.

Slower May Be Better?

In an editorial accompanying the published paper [2], Dr Wilson Tang (Cleveland Clinic, OH) suggests that transient changes in serum creatinine may not necessarily reflect worsening renal function but may actually reflect a desired effect of hemoconcentration. And he proposes that a slower ultrafiltration rate may produce better results.

Tang says the trial "illustrates the overall dismal outcomes in patients in whom the acute cardiorenal syndrome develops." He points out that regardless of treatment strategy, only about 10% of patients had adequate decongestion at 96 hours and more than one-third of patients died or were readmitted to the hospital for acute decompensated heart failure within 60 days, despite overall weight loss.

He concludes that the CARRESS-HF trial reminds that more effort needs to be devoted to preventing the acute cardiorenal syndrome in the first place. He writes: "We may even have to confront the possibility that the pressure to reduce hospital length of stay with a strategy of initial aggressive dialysis may actually result in an increased incidence of the acute cardiorenal syndrome. Perhaps slow and steady may ultimately win the race after all."

The study was supported by grants from the National Heart, Lung, and Blood Institute. Bart reports receiving grant support from Gambro. Disclosures for the coauthors are listed on . Tang reports consulting for Medtronic and St Jude Medical and receiving grants from the National Institutes of Health, Abbott Laboratories, Pfizer/FoldRx, St Jude Medical, and Medtronic. He is an associate editor for the Journal of Cardiac Failure,