A Case of Infiltrative Cardiomyopathy With Refractory Pericardial Effusion Successfully Treated With Empiric Tafamidis.

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare but fatal systemic infiltrative disease with a challenging course of both diagnosis and management. Definitive diagnosis of such rare infiltrative diseases is not feasible for most centers around the world, often leading to a delay in treatment in these patients. We present a case of suspected ATTR-CM manifesting with recurrent decompensated heart failure, tachyarrhythmias, and recurrent pericardial effusion refractory to several lines of treatment. Eventually, the patient had an excellent response to tafamidis therapy, which was initiated empirically in the absence of a definitive diagnosis. Our case elucidates the challenges of treating this rare disease and the potential effectiveness of initiating newer agents such as tafamidis sooner rather than later in the clinical course.