Treatment of cardiac
amyloidosis is determined by the
amyloid type and degree of involvement. Two types of
amyloid commonly infiltrate the heart:
immunoglobulin light-chain amyloid (AL), and
transthyretin amyloid (ATTR), that encompasses other two forms, a hereditary form (hATTR), and a sporadic, age-related wild-type (wtATTR). The prevalence is expected to increase with aging population. The natural history of ATTR
cardiomyopathy includes progressive
heart failure (HF), complicated by arrhythmias and conduction system disease. New
therapies options have been approved or are under investigation. We performed a narrative literature review, manually-searched the reference lists of included articles and relevant reviews. Treatment for cardiac ATTR should be directed towards alleviation of HF symptoms and to slow or stop progressive
amyloid deposition. Conventional HF medications are poorly tolerated and may not alter the
disease progression or symptoms, except perhaps with the administration of
diuretics. There are three approaches of
therapy for ATTR
cardiomyopathy: tetramer stabilizers, inhibition of ATTR
protein synthesis and clearance of deposited fibrils.
Tafamidis diminishes the progression of
cardiomyopathy, functional parameters, improves overall outcome in patients with early disease stages, irrespective of ATTR status and is well tolerated.
Diflunisal has shown promising results in early studies, but at the expense of significant side effects. Two new agents,
antisense oligonucleotides,
patisiran and
inotersen are under investigation in cardiac
amyloidosis.
Patisiran appears to be the most effective treatment for hATTR, although evidence is limited, with a relatively small cardiac subpopulation.
Therapies considering clearance of
amyloid fibrils from tissue remain experimental. In conclusion,
tafamidis is the only approved agent for the treatment of ATTR
cardiomyopathy although multiple other agents have shown promising early results and are undergoing clinical trials. Careful consideration of the type of ATTR, comorbidities and disease stage will be key in deciding the optimal
therapy for ATTR patients.