Fluid Management of Acute Heart Failure With the Reprieve System: The Randomized Controlled FASTR Trial

The Reprieve System is designed to overcome barriers limiting safe and rapid decongestion with individualized automated diuretic titration, real-time diuretic response monitoring, and individualized sodium chloride replacement to prevent cardio-renal dysfunction.

This study aims to establish proof-of-concept that the Reprieve System can facilitate rapid and safe decongestion.

FASTR (Fluid Management of Acute Decompensated Heart Failure Subjects Treated With Reprieve Decongestion Management System [DMS]) was a randomized pilot trial comparing the Reprieve System vs a control strategy of optimal diuretic therapy (ODT) in hospitalized patients with acute heart failure. The primary efficacy endpoint was 24-hour natriuresis, and the primary safety endpoint was a composite of dialysis or doubling of creatinine levels, severe electrolyte abnormalities, hypotension, or hypertensive emergency.

A total of 100 patients were enrolled, with 96 receiving randomized treatment (Reprieve, n = 52; ODT, n = 44). At baseline, the median estimated glomerular filtration rate was 49 mL/min/1.73 m² (Q1-Q3: 36-78 mL/min/1.73 m²) with estimated excess fluid volume of 20 lbs (Q1-Q3: 15-35 lbs). Twenty-four-hour natriuresis was significantly greater with the Reprieve System (1,082 ± 487 mmol) vs ODT (423 ± 290 mmol; P < 0.001). The safety endpoint occurred in 31% of the Reprieve group vs 39% of the ODT group (P = 0.42). Intravenous diuretic therapy duration was shorter with Reprieve [46 hours [Q1-Q3: 29-80 hours]) vs ODT (88 hours [Q1-Q3: 44-143 hours]; P = 0.014). The rate of weight loss (P = 0.002), net fluid loss (P = 0.03), and net natriuresis (P < 0.001) were significantly faster with Reprieve. Change in serum creatinine levels did not differ between the Reprieve (0.19 ± 0.24 mg/dL) and ODT (0.31 ± 0.39 mg/dL; P = 0.07) groups.

In this pilot trial, the Reprieve System safely produced significantly faster decongestion compared with ODT. Confirmation of these findings in the ongoing pivotal trial is required. (Fluid Management of Acute Decompensated Heart Failure Subjects Treated With Reprieve Decongestion Management System [DMS] [FASTR]; NCT05174312).