Evaluation and management of the cardiac amyloidosis

Cardiac amyloidosis describes clinically significant involvement of the heart by amyloid deposition, which may or may not be associated with involvement of other organs. The purpose of this review is to summarize the current state of evidence for the effective evaluation and management of cardiac amyloidosis. Acquired systemic amyloidosis occurs in more than 10 per million person-years in the U.S. population. Although no single noninvasive test or abnormality is pathognomonic of cardiac amyloid, case-control studies indicate that echocardiographic evidence of left ventricular wall thickening, biatrial enlargement, and increased echogenicity in conjunction with reduced electrocardiographic voltages is strongly suggestive of cardiac amyloidosis. Furthermore, newer echocardiographic techniques such as strain and strain rate imaging can demonstrate impairment in longitudinal function before ejection fraction becomes abnormal. Recent observational studies also suggest that cardiovascular magnetic resonance imaging yields characteristic findings in amyloidosis, offering promise for the early detection of cardiac involvement, and the presence of detectable cardiac troponin and elevated B-type natriuretic peptide in serum of affected patients portends an adverse prognosis. Management strategies for cardiac amyloid are largely based on nonrandomized single-center studies. One of the few published randomized studies shows the superiority of oral prednisolone and melphalan compared with colchicine in systemic AL amyloidosis. Intermediate-dose infusional chemotherapy regimes (such as vincristine, adriamycin, and dexamethasone) and high-dose chemotherapy with peripheral stem cell rescue have been used widely, but treatment-related mortality remains substantial with chemotherapy. Recent studies also indicate promising strategies to stabilize the native structures of amyloidogenic proteins; inhibit fibril formation; and disrupt established deposits using antibodies, synthetic peptides, and small-molecule drugs.