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Li Comparative Platelet & Neutrophil Physiology Laboratory

Feline Hypertrophic Cardiomyopathy and Immunothrombosis


What is hypertrophic cardiomyopathy?

Feline hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy in cats affecting nearly 1 in 3 cats. It is caused by thickening of the heart muscle. To date, diagnosis of HCM-affected cats relies solely on echocardiogram or ultrasound performed by a specialist. This greatly hinders our ability to diagnose HCM as many cats with the disease are not symptomatic.

HCM in cats lead to complications such as congestive heart failure and heart rhythm abnormalities but feline arterial thromboembolism (FATE) or “saddle thrombus” is by far the deadliest. It has a mortality rate of up to 70% and in-hospital mortality rate of ~50% within the first 48 hours.

  • Listen to Dr. Li’s podcast on FATE

    • What is immunothrombosis?

    Neutrophil extracellular traps

    Immunothrombosis is the intricate connection between the immune system and coagulation system. In health, the 2 systems work together to promote clot formation, healing of tissues and prevent infections. In diseases, imbalance of the 2 leads to systemic inflammation and thrombosis. It’s hypothesized that immunothrombosis may play a role in disease progression of HCM and predisposes cats to FATE.

    Our study in 2023 found that cats with HCM, even those with subclinical HCM, had increased circulating markers of neutrophil extracellular traps (NETs). NETs are produced from neutrophils, especially after they interact with platelets. Interestingly, NETs could not be found in healthy cats, which suggests that immunothrombosis occurs in cats with HCM.

  • Learn more about NETs

    • Immunothrombosis: Diagnostic marker or therapeutic target?

    Studies in our lab are ongoing to uncover the mechanism of NETs production and significance of NETs as diagnostic biomarker or therapeutic targets.

    Here are some of our ongoing projects in this area:

    • Evaluation of shear-induced platelet activation, neutrophil extracellular trap formation and thrombosis in cats using an in vitro microfluidic model of cardiogenic arterial thromboembolism
    • Evaluation of neutrophil-lymphocyte ratios and platelet-neutrophil ratios in relations to neutrophil extracellular traps formation in cats with hypertrophic cardiomyopathy
    • Uncovering the mechanisms of platelet activation and priming in cats in immunothrombosis