Reprieve Cardiovascular Reports Published FASTR Pilot Study Results Supporting Potential New Approach for Acute Heart Failure Treatment
Reprieve Cardiovascular, a development-stage medical technology company focused on transforming the treatment of acute decompensated heart failure (ADHF), has announced the publication of results from its FASTR randomized pilot study in JACC: Heart Failure. The newly published findings provide additional clinical support for the company’s ongoing FASTR II randomized pivotal trial, which is currently enrolling patients across the United States and Europe.
The publication marks an important milestone for Reprieve Cardiovascular as it seeks to advance a new therapeutic strategy for managing fluid overload in patients hospitalized with acute heart failure. According to the study findings, Reprieve Therapy demonstrated significantly faster decongestion compared with optimal diuretic therapy (ODT), while maintaining a favorable safety profile and avoiding increased risk of kidney injury.
Acute decompensated heart failure remains one of the leading causes of hospitalization worldwide, particularly among older adults. Patients with ADHF frequently experience severe fluid accumulation, or congestion, which can result in shortness of breath, swelling, fatigue, and reduced organ function. Effective fluid removal is central to treatment, yet clinicians have long struggled to balance aggressive decongestion with preservation of kidney function.
Traditional treatment approaches often rely heavily on intravenous diuretics to remove excess fluid. While these medications can reduce congestion, they may also contribute to worsening renal function, electrolyte imbalances, and inconsistent responses among patients. As a result, researchers and clinicians have continued searching for more individualized and physiologically guided approaches to managing heart failure-related fluid overload.
The FASTR pilot study was designed to evaluate whether Reprieve Therapy could improve decongestion outcomes while minimizing complications commonly associated with conventional treatment strategies. The study specifically focused on patients with ADHF experiencing significant fluid volume overload, a population that frequently requires intensive inpatient management.
According to the published data, Reprieve Therapy achieved several clinically meaningful improvements when compared with optimal diuretic therapy. One of the most notable findings was a significant increase in 24-hour total natriuresis, with statistical analysis demonstrating strong significance at P < 0.001. Natriuresis refers to the excretion of sodium in the urine, an important indicator of effective fluid removal in heart failure patients.
The study also demonstrated a significantly greater rate of weight loss among patients receiving Reprieve Therapy, with a P value of 0.002. Weight reduction in ADHF patients is often used as a clinical marker for successful decongestion because excess fluid accumulation contributes substantially to body weight during episodes of worsening heart failure.
In addition to enhanced weight reduction, patients treated with Reprieve Therapy experienced significantly greater net fluid loss and net natriuresis compared with those receiving optimal diuretic therapy alone. Net fluid loss achieved statistical significance with a P value of 0.03, while net natriuresis again demonstrated strong significance at P < 0.001.
Importantly, the improved decongestion outcomes did not appear to come at the expense of patient safety or renal function. Investigators reported no significant differences between the treatment groups in the study’s primary safety endpoint, with a P value of 0.42. Furthermore, there were no significant differences in changes in serum creatinine levels, a commonly used marker of kidney function, between the groups.
Preserving renal function is considered one of the most difficult challenges in acute heart failure management. Aggressive fluid removal strategies can sometimes impair kidney perfusion, potentially leading to worsening renal injury. The ability to achieve faster and more effective decongestion without increasing kidney-related complications represents a potentially meaningful advancement in the field.
Dr. James E. Udelson, Chief of the Division of Cardiology at Tufts Medical Center and principal investigator of the FASTR trial, emphasized the clinical importance of the findings and the potential implications for future patient care.
According to Dr. Udelson, patients enrolled in the FASTR study achieved similar levels of decongestion in approximately half the time compared with patients receiving standard care approaches. He also highlighted the therapy’s ability to improve diuretic efficiency without generating evidence of kidney injury.
Dr. Udelson noted that the findings support the concept of a more individualized and physiologically guided treatment strategy for acute heart failure. Such an approach could potentially improve both the effectiveness and consistency of care while maintaining renal safety, an outcome that has historically proven difficult to achieve in clinical practice.
He also acknowledged the contributions of investigators, study coordinators, and research teams involved in the trial, emphasizing the collaborative effort required to conduct advanced cardiovascular clinical research.
The publication of the FASTR pilot data in a peer-reviewed cardiovascular journal adds an additional layer of scientific validation for Reprieve Therapy and strengthens the foundation for the ongoing FASTR II pivotal trial. Publication in a leading cardiology journal also increases visibility among clinicians, researchers, and healthcare systems evaluating emerging heart failure therapies.
The FASTR II pivotal trial is intended to further evaluate the therapeutic approach in a larger patient population and provide more comprehensive evidence regarding efficacy, safety, and clinical outcomes. The study is currently enrolling participants across multiple sites in both the United States and Europe, reflecting the growing international interest in new approaches to ADHF management.
Reprieve Cardiovascular Chief Executive Officer Mark Pacyna described the publication as an important milestone in the company’s broader effort to rethink how acute heart failure is treated.
Pacyna noted that clinicians have historically faced a difficult trade-off between achieving effective decongestion and protecting kidney function. According to the company, the FASTR findings suggest that an alternative strategy may allow physicians to accomplish both goals simultaneously.
He also emphasized the importance of investing in a large, randomized U.S. pilot study to establish the evidence base needed to advance into the pivotal FASTR II trial. Enrollment in FASTR II is expected to be completed later this year, representing another major step in Reprieve Cardiovascular’s clinical development pathway.
The company believes these milestones may ultimately contribute to redefining the standard of care for patients hospitalized with acute decompensated heart failure.
Heart failure continues to represent a major global healthcare burden, affecting millions of patients and contributing to substantial hospitalization rates, healthcare costs, and mortality. Acute decompensated heart failure episodes are associated with particularly high rates of hospital readmission and disease progression.
One of the central goals of inpatient heart failure treatment is effective decongestion, as residual fluid overload at discharge has been associated with worse outcomes and increased risk of rehospitalization. However, conventional approaches often produce variable responses due to differences in patient physiology, diuretic resistance, and underlying renal function.
The emergence of more personalized therapeutic approaches could therefore play an important role in improving outcomes and reducing the burden associated with recurrent hospitalizations.
Reprieve Cardiovascular’s technology platform is designed to support physiologically guided fluid management by continuously monitoring patient responses and optimizing therapy delivery. This strategy aims to improve fluid removal efficiency while minimizing unintended adverse effects.
The concept aligns with broader trends in cardiovascular medicine toward precision-based therapies and data-driven treatment strategies tailored to individual patient needs. Advances in monitoring technologies, digital health integration, and hemodynamic assessment are increasingly influencing the future direction of heart failure management.
As the FASTR II pivotal trial progresses, clinicians and industry observers will be closely monitoring whether the encouraging pilot data can be replicated in a larger and more diverse patient population. Successful pivotal trial outcomes could potentially support future regulatory submissions and commercialization efforts.
The publication of the FASTR pilot study results also contributes to the growing body of evidence supporting innovative approaches to cardiorenal management in heart failure. Therapies capable of simultaneously improving decongestion while preserving kidney function are viewed as particularly valuable because of the complex relationship between the cardiovascular and renal systems in critically ill heart failure patients.
Beyond clinical outcomes, therapies that reduce hospitalization duration, improve treatment efficiency, and lower readmission risk may also offer important economic benefits for healthcare systems managing rising cardiovascular disease burdens.
With enrollment ongoing in the FASTR II trial and increasing attention focused on advanced heart failure management strategies, Reprieve Cardiovascular continues positioning itself within a rapidly evolving area of cardiovascular innovation. The company’s latest published findings underscore both the unmet need in ADHF treatment and the growing momentum behind efforts to develop safer, faster, and more effective approaches to decongestion therapy.
About Reprieve Therapy
Reprieve Therapy works to remove fluid and sodium through precise administration of diuretics, rapidly finding the optimal dose while replenishing the body with saline to support optimal kidney function. Reprieve Therapy uniquely combines real-time physiological monitoring with recommendations to escalate or end therapy, enabling physicians to tailor treatment to each patient’s specific needs during therapy. This innovative therapy is designed to integrate seamlessly into existing clinical workflows, streamline patient care, and reduce the workload for clinicians treating heart failure patients.
About the FASTR (Fluid management of Acute decompensated heart failure Subjects Treated with Reprieve DMS) Pilot Trial
The FASTR pilot trial was a multicenter, randomized, controlled trial designed to evaluate the Reprieve Therapy in optimizing decongestion in ADHF patients. The trial enrolled a total of 100 patients, 96 of whom were randomized 1:1 to receive treatment with Reprieve Therapy or optimal diuretic treatment based on best-practice dosing.
Patients with ≥10 lbs (4.5 kg) of estimated volume overload were included in the trial. The primary efficacy endpoint was total urine sodium output at 24 hours post-treatment initiation, while the primary safety endpoint was the composite of acute kidney injury, severe electrolyte abnormalities, symptomatic hypotension, and hypertensive emergencies.
Reprieve Cardiovascular is currently enrolling patients in the FASTR II randomized pivotal trial across sites in the United States and Europe. The trial is designed to support a future premarket approval submission to the U.S. Food and Drug Administration.
About Acute Decompensated Heart Failure (ADHF)
Acute decompensated heart failure (ADHF) is characterized by the sudden or gradual onset of symptoms such as difficulty breathing, leg or feet swelling, and fatigue, often requiring unplanned office visits, emergency room care, or hospitalizations, with an average stay of more than five days. Nearly 1 in 4 patients are readmitted to the hospital within 30 days to address fluid volume overload, and approximately half are readmitted within six months. Managing fluid removal in ADHF patients has been a persistent challenge, as the primary treatment of diuretics is difficult to administer precisely without real-time information on patient response. This can lead to an increased risk of kidney injury, prolonged hospital stays, inadequate fluid removal at discharge, and frequent readmissions.
About Reprieve Cardiovascular, Inc.
Reprieve Cardiovascular is committed to advancing the treatment of heart failure by developing groundbreaking technologies that bring intelligence to decongestion management. The company’s innovative therapies aim to improve the lives of over 25 million heart failure patients worldwide. Headquartered in Milford, Massachusetts, Reprieve Cardiovascular is dedicated to pioneering solutions that address the complex challenges of heart failure management.
