Primary and familiar cardiac amyloidosis: from epidemiology to the clinical role of cardiac biomarkers

Cardiac amyloidosis (CA) is an increasingly recognized infiltrative disease due to amyloid fibrils deposition in the myocardium; the two forms that most frequently involve the heart are light chain (AL) and transthyretin (ATTR) amyloidosis. Cardiac troponin (cTn) is the biomarker of choice for the detection of myocardial injury and is frequently found elevated in patients with CA, particularly with high-sensitivity assays (hs-cTn, either T or I). Multiple mechanisms of myocardial injury in CA have been proposed, including cytotoxic effect of amyloid precursors, interstitial amyloid fibrils infiltration, coronary microvascular dysfunction and amyloid/non-amyloid related coronary artery disease, diastolic dysfunction and heart failure. Moreover, acute on chronic myocardial injury can also be present, sometimes with sign and symptoms of myocardial ischemia. Regardless of the mechanisms, cTn values have relevant prognostic and diagnostic implications in both AL and ATTR amyloidosis. In this thesis, several aspects related to these premises have been addressed, starting from the epidemiology of this condition in the Veneto Region (Italy), moving to the diagnostic role of hs-cTnT in patients with suspected ATTR-CA and to the prognostic role of hs-cTnI in patients diagnosed with ATTR-CA (particularly wild-type), up to the analysis of a peculiar symptom in patients with CA (chest pain) and the relationship of hs-cTnI with this symptom in the acute setting.