Reprieve System Safely Aids Decongestion in Acute HF: FASTR Pilot RCT

BOSTON, MA—The Reprieve decongestion management system (Reprieve Cardiovascular) appears to safely manage patients hospitalized with acute heart failure (HF) and significant volume overload, according to top-line results from the randomized FASTR pilot study.

Use of the system led to improvements in sodium output, urine output, and weight loss, while preserving kidney function, compared with a diuretic strategy based on contemporary randomized trials, James Udelson, MD (Tufts University School of Medicine, Boston), reported here at THT 2025.

Presentation THT 2025

Fluid Management of Acute Decompensated Heart Failure Subjects Treated With Reprieve Decongestion Management System (DMS) – The FASTR Trial

There were no concerning safety signals, and the risk of death or rehospitalization for HF through 3 months was numerically—but not significantly—lower among patients managed with the Reprieve system.

The primary therapeutic goal for patients hospitalized for acute HF is decongestion, but about 20% fail to lose weight and half still have some degree of congestion when they leave the hospital, Udelson noted. Potential contributors to suboptimal decongestion, he said, are poor fidelity of data to guide therapy, insufficient dosing and slow uptitration of diuretics, diuretic resistance, and a fear of worsening kidney function.

The Reprieve system was designed to address these problems, said Udelson. The algorithm, driven by urine sodium measurements, quickly identifies the therapeutic diuretic dose, maintains therapeutic dosing during diuresis (with uptitration performed if necessary), and preserves renal function and prevents diuretic resistance with a saline infusion.

Udelson said the new top-line data lay the groundwork for the pivotal FASTR II trial, an investigational device exemption (IDE) study that will start in the first half of this year.

The Pilot FASTR Trial

The FASTR pilot/feasibility study included 96 patients (mean age 63 years; 55% men) hospitalized with acute heart failure and at least 10 lbs of volume overload, as estimated by treating clinicians. They were randomized to management with the Reprieve system or with optimal diuretic therapy.

Median estimated excess fluid was 20 lbs in the Reprieve group and 24 lbs in the control group. Patients with reduced or preserved ejection fraction were included, with a mean LVEF of about 38%.

In the first 72 hours, the furosemide dose delivered was much higher in the Reprieve arm. Duration of furosemide was lower in patients managed with the system (mean 41.7 vs 55.8 hours; P < 0.001) and the proportion of patients who had IV diuresis completed by 72 hours was higher (71% vs 41%; P = 0.003). Mean IV saline replacement in the Reprieve group was 3.3 L per 24 hours.

The primary efficacy outcome was 24-hour urine sodium output, and this was greater in the Reprieve-managed patients (about 1,100 vs less than 500 mmol; P < 0.001). Use of the system was associated with significant increases in mean total urine output (9.4 vs 4.5 L), net sodium excretion (mean 587 vs 436 mmol), and mean weight loss (3.8 vs 2.7 kg).

Management with Reprieve was safe, with no increase in a composite safety outcome consisting of acute kidney injury, severe electrolyte abnormalities, and symptomatic hypotension compared with the control group (16 vs 19 events; P = 0.35). The risk of death or rehospitalization for HF through 3 months also trended lower among patients managed with the Reprieve system (HR 0.64; 95% CI 0.31-1.30). Renal function was unaffected, with no difference between groups in serum creatinine increase.

Moreover, rates of urinary tract infection (UTI) and catheter-associated UTI were numerically lower among patients managed with the Reprieve system. That’s biologically plausible, Udelson said, because of a brisk urine flow, a shorter duration of catheter placement, and catheter occlusion alarms with the Reprieve system.

Compared with strategies explored in prior diuretic trials, including CLOROTIC, DOSE-AHF, ADVOR, and PUSH-AHF, the Reprieve system led to more weight loss during active therapy and lower absolute excess of worsening renal function versus control, Udelson said.

He acknowledged, however, some limitations of the study, including the open-label design with a modest number of patients, the possibility that the control strategy did not reflect real-world practice, and the preliminary nature of the data.

Questions Abound

Commenting for TCTMD, Nancy Sweitzer, MD, PhD (WashU Medicine, St. Louis, MO), editor-in-chief of Circulation: Heart Failure, noted that in practice, “we don’t give enough diuretic to patients who are in the hospital. We don’t give enough diuretic fast enough.”

In that context, the Reprieve system “just seems to be giving a lot of diuretic really fast,” she said. “But doing that in a way that clinicians are comfortable that they’re not harming people is really critical. And at least initially there’s not much signal for harm, which is great.”

The impact of shortening the time it takes to decongest patients could be substantial, Sweitzer indicated. “If you could shorten length of stay by a day in every heart failure admission in the country, obviously that would be a huge cost-savings in the United States because there’s a lot of heart failure.”

But there are many unanswered questions, said Sweitzer, who wondered whether the saline infusion is necessary. In addition, she said, it’s unclear whether patients were truly decongested at the end of treatment and how well other guideline-directed medical therapies for HF were administered in the hospital.

It’s not known how well the Reprieve system will perform against a better-treated control group, which is an important issue considering the expense that will come with using the technology, Sweitzer said. It’s possible other, less-expensive strategies—like use of urine sodium-guided diuretic protocols—may achieve the same result.

Beyond the initial hospitalization, keeping patients from returning is critical, she added.

“More effective decongestion in the hospital is a step on the road, but it’s not the entire road, and we need to follow that up with effective care afterward and effective dosing of diuretics afterward,” Sweitzer said. “We’re terrible at that, honestly. Readmission is so high partly because we don’t decongest people in the hospital, but also partly because it’s hard to maintain what happens in the hospital in the outpatient setting for many reasons.”