ATTR Amyloid Cardiomyopathy: Characterization of Extracellular Vesicles as Potential Disease Stratifiers and Prognostic Biomarkers

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive infiltrative disease caused by the deposition of misfolded transthyretin protein in the myocardium. Despite advances in imaging and treatment, early detection and accurate risk stratification remain major challenges, often resulting in delayed diagnosis and worse clinical outcomes.

This prospective observational study will enroll 70 adult participants, distributed into four predefined groups:

• ATTR-CM with myocardial dysfunction (n = 20)
• Hereditary ATTR with predominant neurologic involvement (n = 20)
• Genotype-positive individuals without clinical manifestation (n = 10)
• Healthy controls (n = 20)

All participants will undergo blood collection for extracellular vesicle (EV) isolation and molecular profiling. EVs are nanoscale particles released by cells that carry proteins, lipids, and nucleic acids reflective of their cellular origin and physiological state, potentially serving as minimally invasive biomarkers.

Participants with cardiac involvement will additionally undergo standardized cardiac evaluations, including echocardiography, cardiac MRI, and nuclear imaging when indicated. Clinical data, functional status, and laboratory parameters will be correlated with EV characteristics to assess their association with disease severity and progression.

By integrating EV profiling with clinical and imaging findings across different phenotypes and disease stages, this study aims to identify biomarkers capable of improving diagnostic accuracy, tracking disease evolution, and supporting personalized care strategies in ATTR amyloidosis.

Inclusion criteria

• Adult patients aged 18 years or older;
• Confirmed diagnosis of transthyretin cardiac amyloidosis (TTR-CA), with or without myocardial dysfunction, according to established diagnostic criteria;
• Willingness to comply with study procedures and requirements;
• Ability to provide written informed consent.

Exclusion criteria

• Presence of other significant cardiac conditions that may interfere with study outcomes, such as severe coronary artery disease or major valvular disease;
• Inability to provide informed consent or to participate in the required clinical assessments and examinations.