Methods: This prospective, single-center study will include consecutive patients diagnosed with ATTR cardiomyopathy (GROUP 1, n=30), asymptomatic carriers of pathogenic TTR variants (GROUP 2, n=30), and a matched control group of healthy volunteers (GROUP 3 , n=20). Material for research was collected and secured from all study participants. After giving informed consent, all patients will be tested using the ELISA method from peripheral blood (enzyme-linked immunosorbent assay) GDF15, ST2, TTR, TIMP-1, MMP-9, galectin-3, NfL. The values of these biomarkers will be compared in subgroups and correlated with clinical data, laboratory test results, echocardiography including analysis of left ventricular global strain (GLS), and scintigraphy. Additionally, the prothrombotic potential of plasma will be tested in both groups of patients using the calibrated automatic thrombogram (CAT) method, in accordance with the protocol previously used in the laboratory Expected results: The project will provide information on the value of biomarkers in the assessment of ATTR cardiomyopathy, especially in the assessment of asymptomatic carriers of pathogenic TTR variants, which may translate into the creation of a diagnostic algorithm for early identification of the development of the disease. Moreover, it will allow us to determine whether patients with cardiac ATTR are characterized by a prothrombotic state, which has not yet been described in the literature and may have potential clinical implications.