Scientists Identify Two Heart Scar Types, Paving Way for Targeted Treatments

A team of Israeli researchers from the Weizmann Institute has made a major medical breakthrough by identifying two distinct mechanisms behind heart fibrosis (scarring). Their findings, published in the journal Cell Systems, could revolutionize treatments for heart disease by allowing targeted therapies based on the type of scarring a patient has.

Challenging Medical Assumptions

Scar tissue forms in the heart when muscle cells are damaged—often due to heart attacks. While scarring helps maintain structural integrity, it weakens the heart’s ability to contract effectively, leading to long-term damage.

Traditionally, medical science viewed all heart fibrosis as uniform. However, this research challenges that notion by showing that two different processes drive scarring:

1. Hot Fibrosis – Involves macrophages, immune cells linked to inflammation and fever, actively interacting with myofibroblasts (cells that produce scar tissue).
2. Cold Fibrosis – Develops without macrophages. Instead, myofibroblasts sustain the fibrosis independently, continuously producing scar-forming molecules.

Mathematics Meets Medicine

This groundbreaking study was born from an unexpected collaboration between:

• Eldad Tzahor, a heart disease expert.
• Uri Alon, a scientist who developed a mathematical model to classify scar tissue formation in different organs.

At first, Tzahor doubted that scarring could be categorized with such a simple model, but after testing it on real human heart samples, the results proved its accuracy.

Potential for New Targeted Treatments

Understanding whether a patient has hot or cold fibrosis could transform heart disease treatment. Doctors may soon:

• Prescribe anti-inflammatory or immune-modulating drugs for hot fibrosis.
• Use fibroblast-blocking drugs to prevent cold fibrosis from worsening.

This research could also lead to new diagnostic tools that help doctors differentiate between fibrosis types in patients.

Beyond the Heart: Impact on Other Diseases

Fibrosis affects multiple organs, including the lungs (pulmonary fibrosis), kidneys, and liver (cirrhosis). Researchers believe that the hot-cold fibrosis distinction may apply to scars from strokes or even cancerous tissues.

“This collaboration changed my understanding of the heart,” said Uri Alon. “Now, future studies can explore whether this classification applies to other organs as well.”

A Step Toward Personalized Medicine

With millions suffering from heart disease and fibrosis-related conditions, this discovery paves the way for tailored treatments, potentially improving survival rates and quality of life worldwide.