Guardian of fluid balance

Wrocław, Poland & Durham, NC (October 2025) — A new study published in the European Journal of Heart Failure reveals that the speed of lymph flow in the legs may determine how well patients respond to diuretics — a key therapy for acute heart failure (AHF).

Researchers from Wroclaw Medical University and Duke University School of Medicine found that patients with faster lymphatic flow in their lower limbs experienced significantly better diuretic responses, shedding new light on the role of the lymphatic system in fluid balance and heart failure treatment.

The missing link in decongestion therapy

Heart failure, a condition in which the heart cannot pump enough blood to meet the body’s needs, often leads to fluid buildup and swelling. While diuretics help remove excess water, some patients show little or no improvement — a phenomenon known as diuretic resistance.

The research team used indocyanine green (ICG) lymphography, a near-infrared fluorescent imaging technique, to visualize lymphatic flow in 65 hospitalized AHF patients. Three hours after receiving standard furosemide treatment, patients underwent imaging of the lower limbs to measure how quickly lymph fluid moved through the vessels.

The results were striking:

• In 95% of responders, lymph flow reached above the ankle within 10 minutes, compared to 73% of non-responders.

• Significant lymph flow (≥10 cm) was observed in 88% of responders versus 45% of non-responders.

• The median lymph flow distance was 50 cm in responders and only 10 cm in non-responders.

“Our research shows a clear link between faster lymph flow and a stronger diuretic response in acute heart failure,” said Dr. Barbara Ponikowska, lead author of the study. “It suggests that lymphatic efficiency may be a missing component in understanding why some patients fail to respond to standard therapies.”

Lymphatics - an overlooked circulatory partner

The findings highlight the lymphatic system as a crucial yet often ignored player in maintaining fluid balance. When diuretics draw water from the bloodstream, the lymphatic system must replenish plasma volume by returning interstitial fluid. If lymphatic transport is sluggish, diuresis stalls - much like a pump running dry because the drainpipe is blocked.

The study also revealed that higher aldosterone levels, a hormone known to promote salt and water retention, were associated with slower lymph flow and poorer treatment outcomes. This may open new therapeutic pathways combining diuretic and hormonal modulation strategies.

“By targeting lymphatic function, we may be able to support decongestion more effectively and personalize therapy for heart-failure patients,” Dr. Ponikowska added.

New direction for clinical research

Although preliminary and limited by its single-center design, the study introduces lymphatic flow as a potential biomarker and therapeutic target in acute heart failure. Future research will aim to develop non-invasive, real-time monitoring tools for lymphatic circulation, technologies that could transform the way clinicians assess and manage fluid overload.

Article: Lower extremity lymphatic flow is associated with diuretic response in acute heart failure
Journal: European Journal of Heart Failure
DOI: 10.1002/ejhf.3655
Authors: Barbara Ponikowska et al., Wroclaw Medical University, Duke University School of Medicine