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Mechanical devices challenge diuretics-only approach to acute heart failure

Mechanical devices challenge diuretics-only approach to acute heart failure

New Capabilities

First-in-class lymphatic drainage catheter posts positive feasibility results as three device makers race to crack a problem drugs have not solved

December 31st, 2026: LYMPH-HF pivotal trial planned to begin

Overview

A catheter threaded into a vein in the neck pulled an average 6.8 kilograms of excess fluid out of 40 hospitalized heart failure patients without damaging their kidneys. Six months later, 82.5 percent were still alive and out of the hospital.

Acute heart failure kills almost one in four patients within a year of admission, and about 30 percent end up readmitted within 90 days. The DELTA-HF results, published May 10 in the European Journal of Heart Failure, point to a mechanical alternative to the diuretic drugs that have been the standard for half a century.

Why it matters

Heart failure hospitalizations send roughly a third of patients back within 90 days. A new class of devices is trying to break that cycle.

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Key Indicators

6.8 kg
Average fluid removed
Mean weight loss at hospital discharge for the 40 patients treated with the eLym System.
82.5%
Alive and out of hospital at 6 months
Freedom from heart-failure rehospitalization and death in DELTA-HF.
100%
Successful device deployment
The catheter reached and operated at its target site in every case attempted.
~30%
Typical 90-day readmission rate
The persistent problem that drug therapy alone has not solved.
40
Patients in DELTA-HF
Single-arm feasibility study. The randomized LYMPH-HF pivotal trial begins later in 2026.

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People Involved

William Brangham
William Brangham
Professor of Medicine at The Ohio State University Wexner Medical Center
 Jorge Nuche
Jorge Nuche
Cardiologist at Hospital Universitario 12 de Octubre, Madrid

Organizations Involved

WhiteSwell
WhiteSwell
Medical device company
Sponsor of the DELTA-HF and upcoming LYMPH-HF trials

Galway-based medical device firm developing a catheter that drains excess lymphatic fluid through the thoracic duct.
Reprieve Cardiovascular
Reprieve Cardiovascular
Medical device company
Direct competitor in the acute-heart-failure decongestion space

Maker of an automated diuresis system that times IV saline and diuretic delivery to speed safe fluid removal.
AquaPass Medical
AquaPass Medical
Medical device company
Direct competitor pursuing a non-invasive decongestion approach

Maker of a wearable garment that uses warm air to evaporate fluid through the skin.
U.S. Food and Drug Administration
U.S. Food and Drug Administration
Federal regulatory agency
Has granted Breakthrough Device Designation to multiple decongestion devices

The U.S. regulator that approves medical devices for sale in the country.

Timeline

  1. LYMPH-HF pivotal trial planned to begin

    Clinical Trial

    WhiteSwell plans to start its randomized confirmatory trial across the U.S., Canada, Europe, and Israel later in 2026.

  2. DELTA-HF primary results released

    Clinical Trial

    WhiteSwell reports 6.8 kg average fluid loss, 100 percent deployment success, and 82.5 percent freedom from death and rehospitalization at 6 months in 40 patients.

  3. CVRx starts BENEFIT-HF for Barostim

    Clinical Trial

    A separate 2,500-patient trial begins enrolling to test whether a neck-implanted nerve stimulator cuts heart-failure death. Different mechanism, same patient pool as the decongestion devices.

  4. FASTR pilot meets primary endpoints

    Clinical Trial

    Reprieve Cardiovascular's automated diuresis system shows faster sodium and fluid removal versus standard diuretic therapy in 96 patients at THT 2025.

  5. WhiteSwell publishes DELTA-HF design

    Publication

    European Journal of Heart Failure publishes the rationale for testing thoracic-duct drainage in acute heart failure.

  6. CARRESS-HF reverses momentum for ultrafiltration

    Clinical Trial

    A larger NIH-funded trial shows ultrafiltration is no better than a stepped diuretic protocol and worsens kidney function. The result sets the device field back by years.

  7. UNLOAD trial favors ultrafiltration over diuretics

    Clinical Trial

    A 200-patient randomized study finds the Aquadex ultrafiltration device removes more fluid and cuts 90-day readmissions versus IV diuretics, opening the door to mechanical decongestion.

Scenarios

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1

LYMPH-HF confirms benefit and FDA clears first lymphatic-drainage device

A randomized win in LYMPH-HF, especially on rehospitalization, would let WhiteSwell file with the FDA on the back of its Breakthrough Device Designation. That path takes roughly 12 to 18 months from completed pivotal trial to a decision. The eLym System would then enter U.S. cath labs as the first device aimed directly at the thoracic duct, ahead of or alongside Reprieve's FASTR II readout.

Discussed by: WhiteSwell investor materials; Heart Failure 2026 commentators including European Society of Cardiology faculty
Consensus —
2

Pivotal trial fails to replicate single-arm gains

Single-arm studies with no placebo group routinely overshoot. CARRESS-HF turned a promising ultrafiltration story into a long pause for the field once a real control arm was added. If LYMPH-HF shows no advantage over optimized IV diuretics, or shows higher procedure-related harm, WhiteSwell could face the same setback. The 5 percent serious adverse event rate in DELTA-HF, while modest, will be watched closely against a non-invasive comparator.

Discussed by: Skeptical heart failure researchers citing the UNLOAD-to-CARRESS-HF reversal
Consensus —
3

Competing decongestion devices split the market

Three companies are targeting the same patients using three different mechanisms: a catheter in the neck (WhiteSwell), a closed-loop IV pump (Reprieve), and a wearable evaporative robe (AquaPass). If two or more get cleared in the next two to three years, hospitals may stratify by patient profile rather than pick one winner. That fragments revenue but speeds adoption of the general idea that drugs alone are not enough.

Discussed by: MDDI Online; Cardiac Interventions Today; medtech analysts covering the FDA Breakthrough pipeline
Consensus —
4

Diuretic-resistant patients drive uptake without a mortality signal

Even if the device class never proves it saves lives, it may win a foothold in the roughly 25 to 30 percent of admitted patients who stop responding to IV diuretics. Those patients have the worst outcomes and the fewest options. A pivotal trial that hits decongestion and length-of-stay endpoints, even without a survival benefit, could be enough for guidelines to recommend devices in that subgroup.

Discussed by: Heart Failure Society of America device guidance authors; Cleveland Clinic faculty on device-based heart failure therapy
Consensus —

Historical Context

UNLOAD trial validates ultrafiltration (2007)

September 2007

What Happened

A 200-patient randomized trial published in the Journal of the American College of Cardiology compared the Aquadex ultrafiltration device against intravenous diuretics in hospitalized heart failure patients. The device group lost more weight at 48 hours and had fewer rehospitalizations at 90 days. CHF Solutions, the device's maker, gained early commercial traction.

Outcome

Short Term

Ultrafiltration entered U.S. hospitals as an option for diuretic-resistant patients. Investment in mechanical decongestion accelerated.

Long Term

Aquadex still exists, now owned by Nuwellis, but adoption stayed modest. The single positive trial was not enough to displace diuretics from first-line care.

Why It's Relevant Today

DELTA-HF sits in the same niche UNLOAD opened. WhiteSwell is making the same bet that a device can do what diuretics cannot, while trying to avoid the pitfalls that limited Aquadex.

CARRESS-HF stalls the device field (2012)

November 2012

What Happened

An NIH-funded randomized trial of 188 patients with worsening kidney function tested ultrafiltration against a stepped diuretic protocol. Published in the New England Journal of Medicine, it found ultrafiltration was no better at fluid removal and caused more kidney injury and adverse events.

Outcome

Short Term

Enthusiasm for ultrafiltration collapsed almost overnight. Insurance coverage tightened and many programs shelved their devices.

Long Term

For nearly a decade, no major sponsor pursued a fresh device-based decongestion trial. The current wave of WhiteSwell, Reprieve, and AquaPass studies is the first serious return to the question.

Why It's Relevant Today

This is the cautionary tale every investor in the current wave knows. A positive feasibility trial in 40 patients can flip when a real control arm and 200 patients show up. LYMPH-HF must clear a bar that ultrafiltration could not.

CardioMEMS wins FDA approval (2014)

May 2014

What Happened

The FDA approved the CardioMEMS HF System, a small pressure sensor implanted in the pulmonary artery to monitor fluid status remotely. The CHAMPION trial had shown a 28 percent reduction in heart failure hospitalizations. William Abraham, who later led DELTA-HF, was a principal investigator on CHAMPION.

Outcome

Short Term

CardioMEMS became the first FDA-approved implantable hemodynamic monitor for heart failure. Abbott acquired the technology in 2017.

Long Term

Use grew slowly because of reimbursement and patient selection issues, but the device established that targeted device-based interventions could cut rehospitalizations enough to win approval.

Why It's Relevant Today

CardioMEMS shows the regulatory path is open for a heart failure device whose primary endpoint is fewer hospitalizations rather than fewer deaths. That is the path the new decongestion devices are trying to follow.

Sources

(7)
+1
GlobeNewswire Health Technology Net European Journal of Heart Failure Cardiac Interventions Today TCTMD Journal of Cardiac Failure GlobeNewswire