Cardiac amyloidosis, traditionally considered a rare and dire disease, is receiving increasing attention as sophisticated diagnostics are identifying more patients and novel therapies are emerging to combat it. Among the latest signs of progress are the encouraging results of the ATTR-ACT study of the drug tafamidis presented as a late-breaking trial at the European Society of Cardiology Congress in late August and simultaneously published online by the New England Journal of Medicine.
Tafamidis was studied for treating one of the two main types of cardiac amyloidosis — transthyretin (ATTR) amyloidosis, which is caused by misfolding of the liver-derived transthyretin protein, leading to amyloid fibril formation and deposition in the myocardium. Although both types cause cardiac amyloidosis, ATTR amyloidosis is a very distinct disease from light chain (AL) amyloidosis, in which plasma cells in the bone marrow produce an amyloidogenic light chain fragment. The pathophysiology, prognosis and treatment of the two types differ considerably.