Clinical, laboratory and multimodality approach to cardiac amyloidosis

Abstract

Amyloid cardiomyopathy is caused by deposition of insoluble amyloid proteins in the heart. It may have a primary cause, be inherited or secondary. ATTRwt cardiomyopathy (wild type) and immunoglobulin light chain (AL) amyloidosis are the most common types. It is generally manifested by dyspnea, fatigue and edema resistant to diuretic therapy. The diagnosis must be based on existence of typical scenarios and “red flags”, such as, identification of left ventricular hypertrophy unjustified associated with electrocardiographic pattern of low voltage, patients with aortic valve stenosis or undergoing TAVI, bilateral carpal tunnel syndrome ... Serum and urinary immunofixation and the presence of monoclonal light chains generally confirms or excludes the hypothesis of AL. The investigation of amyloid deposits by biopsy is essential before initiating therapy. Bone scintigraphy is sensitive for detecting TTR-type cardiac amyloidosis and allows non-invasive clinical diagnosis in most situations. Older patients with an echocardiogram /cardiac magnetic ressonance suggestive of cardiac amyloidosis and a technetium scan showing myocardial uptake are strongly suspected of wild-type TTR amyloidosis (ATTR wt). Genetic testing must be performed to differentiate ATTRv from ATTRwt. The specific treatment of each amyloidosis includes the management of clinical syndromes, such as heart failure, cardiac conduction disorders, nephrotic syndrome and neuropathy. The treatment shoud be managed by a multidisciplinary team working at a specialized center. Treatment options should be personalized and decisions should be shared amongst the team. The costs of pharmacological treatment of transthyretin amyloid cardiomyopathy may be challenging in our country as a result of the expected increase in use cost-effectiveness/budgetary impact.