This study explores whether extracellular vesicles (EVs) tiny particles released into the bloodstream by cells can serve as early and minimally invasive biomarkers for transthyretin amyloid cardiomyopathy (ATTR-CM). Because ATTR-CM is often diagnosed only after significant heart damage has occurred, there is an urgent need for earlier detection methods.

The study will enroll individuals with different clinical presentations of transthyretin amyloidosis, along with healthy controls. Participants will undergo blood sampling, cardiac imaging (including echocardiography, cardiac MRI, and scintigraphy when indicated), and molecular EV analysis.

By comparing EV profiles across groups, the study aims to determine whether these vesicles reflect early cardiac involvement, track disease progression, and support more accurate and timely diagnosis. Ultimately, this research seeks to improve clinical decision-making and patient outcomes in ATTR cardiomyopathy.

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.

This study will enroll adult participants aged 18 years or older, including patients with confirmed transthyretin cardiac amyloidosis (with or without myocardial dysfunction), as well as healthy volunteers without known cardiac disease. The population includes individuals with different clinical presentations of ATTR and matched controls for comparative analysis.