WhiteSwell Reports Encouraging DELTA-HF Results for Novel Lymphatic Heart Failure Device

WhiteSwell has reported positive primary results from the DELTA-HF feasibility trial evaluating its investigational eLym System in patients with acute decompensated heart failure (ADHF).

The findings were presented at the Heart Failure 2026 Congress in Barcelona and simultaneously published in the European Journal of Heart Failure.

The results highlight a potentially new treatment paradigm for heart failure by targeting the lymphatic system rather than focusing exclusively on conventional diuretic-based fluid removal.

Why Acute Decompensated Heart Failure Remains a Major Problem?

ADHF is one of the leading causes of hospitalization worldwide. Patients experience:

• Severe fluid overload
• Breathing difficulty
• Fatigue
• Tissue swelling (edema)

Current treatment primarily relies on IV diuretics to remove excess fluid. However, many patients:

• Respond poorly to diuretics
• Leave the hospital incompletely decongested
• Face high readmission rates

Residual congestion after discharge is considered one of the strongest predictors of rehospitalization and mortality.

A Different Strategy: Targeting the Lymphatic System

Unlike standard heart failure therapies, WhiteSwell’s approach focuses on improving lymphatic drainage.

How the eLym System Works?

The eLym System is a minimally invasive catheter-based device designed to:

• Create a localized low-pressure zone near the thoracic duct outflow
• Support movement of excess fluid from tissues back into circulation
• Enhance decongestion alongside IV diuretics

The device is deployed through:

• The left internal jugular vein
• The innominate vein

It uses an endovenous micro-axial impeller pump to reduce thoracic duct pressure and restore lymphatic flow. The system has already received:

• FDA Breakthrough Device Designation from the U.S. Food and Drug Administration

DELTA-HF Trial Overview

The DELTA-HF study was an early feasibility, multicenter, single-arm trial evaluating the safety and performance of the eLym System in hospitalized ADHF patients.

Patient Population

The enrolled patients represented a difficult-to-treat population:

• Hospitalized despite high home diuretic use
• Multiple comorbidities
• Many considered poor responders to standard therapy

Treatment Details

• 40 patients treated
• Average therapy duration: 23.1 hours
• eLym therapy combined with IV diuretics
• Six-month follow-up period

Key Clinical Findings

Strong Decongestion Signals

Patients experienced substantial fluid reduction:

• Mean weight loss: 6.8 kg by discharge
• Median modified EVEREST congestion score improved from 5 to 0

The improvement remained stable through six months.

Stable Kidney Function

One major challenge in aggressive heart failure decongestion is kidney injury.

In DELTA-HF:

• Serum creatinine remained stable
• Median creatinine decreased slightly from 1.26 mg/dL to 1.15 mg/dL

This suggests decongestion may have occurred without major renal compromise.

Promising Six-Month Outcomes

At six months:

• 82.5% of patients remained free from heart failure hospitalization and death

Investigators noted that patients with severe diuretic resistance often experience event rates approaching 50% within six months under standard care alone.

Safety Findings

The device demonstrated:

• 100% deployment success rate
• Thoracic duct pressure reduction in 98% of patients

However, safety concerns remain important.

Serious Adverse Events

Two procedure-related serious adverse events occurred:

• One patient death
• One hypotensive event that resolved without long-term consequences

Given the invasive nature of the procedure and the severity of the patient population, larger randomized studies will be necessary to better define risk-benefit balance.

Why the Lymphatic System Matters in Heart Failure?

The lymphatic system plays a central role in fluid regulation. In healthy individuals:

• Excess tissue fluid is continuously drained back into circulation

In ADHF:

• Elevated venous pressure impairs lymphatic drainage
• Fluid accumulates in tissues and organs
• Congestion worsens progressively

WhiteSwell’s strategy attempts to directly restore lymphatic outflow rather than relying solely on kidney-driven fluid removal.

This represents a fundamentally different mechanistic approach compared with most heart failure therapies.

Next Step: The LYMPH-HF Pivotal Trial

Following the DELTA-HF feasibility results, WhiteSwell plans to launch the randomized LYMPH-HF trial later this year.

Planned LYMPH-HF Study

The trial will evaluate:

• eLym System plus optimal diuretic therapy
  vs.
• Optimal diuretic therapy alone

The study is expected to enroll patients across:

• The United States
• Canada
• Europe
• Israel

This next-stage trial will be critical for validating whether lymphatic-targeted therapy can improve hard clinical outcomes in ADHF.

The Bigger Picture for Heart Failure Innovation

Heart failure remains one of the largest unmet needs in cardiovascular medicine.

Despite major advances in chronic heart failure drugs:

• Hospitalization rates remain extremely high
• Congestion management is still difficult
• Diuretic resistance remains a major challenge

The eLym System introduces a new category of therapy focused on:

• Interstitial fluid clearance
• Lymphatic restoration
• Mechanical decongestion support

If successful in larger studies, it could expand the treatment toolbox beyond traditional pharmacology.

Conclusion

The DELTA-HF feasibility study provides encouraging early evidence that eLym System may help improve decongestion in difficult-to-treat ADHF patients.

For WhiteSwell, the combination of strong decongestion results, stable renal function, and promising six-month outcomes supports further development of this novel lymphatic-based treatment strategy.

The upcoming randomized LYMPH-HF trial will now determine whether targeting the lymphatic system can meaningfully reduce hospitalization and mortality in one of cardiovascular medicine’s most burdensome conditions.