ATTR-CM can only be treated in a limited number of ways, and this article analyzes and compares the currently available treatment options.
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare, debilitating disease with high mortality. ATTR-CM is caused by transthyretin (TTR) amyloid protein build ups in the myocardium and other organs, in most cases the peripheral and autonomic nervous system. In general, ATTR-CM cannot be treated with ordinary heart failure medications due to the difficulty of balancing the high filling pressure associated with restricted ventricular volume with the low cardiac output. Tafamidis is the only approved agent for ATTR-CM, although other off-label treatments are commonly used in ATTR-CM patients. The purpose of this study, published in the Journal of Clinical Medicine, is to describe the current and future therapies available for ATTR-CM, as well as to describe the difficulties that may be faced in bringing them to fruition.
The pathophysiology of ATTR-CM is distinctive, and is characterized by restrictive ventricular filling and reduced stroke volume. Loop diuretics are used to reduce cardiac congestion, but blood pressure must be monitored adequately to reduce adverse effects related to renal perfusion and cardiac output. Epigallocatechin-3-gallate (EGCG) is one current treatment option that can prevent TTR formation and is well-tolerated in most patients. Green tea extract, which contains EGCG, has been shown to reduce left ventricular wall mass and thickness, although the results of one study did not show an overall survival benefit.
For the past several decades, liver transplantation has been considered the only approach that can stop the progression of ATTR-CM. However, it does not provide a total cure for the disease. In 2019, tafamidis was approved by the FDA as the first pharmacological treatment for ATTR-CM. Various other off-label medications, such as revusiran, inotersen, and patisiran are also being explored. In most cases, further placebo-controlled studies are needed to assess how effective these drugs are for ATTR-CM. The authors conclude that the treatment landscape for ATTR-CM treatment is still growing, but is currently fairly limited, especially for patients with contraindications to tafamidis, or who have no insurance coverage.
Reference
Tschöpe, C., & Elsanhoury, A. (2022). Treatment of Transthyretin Amyloid Cardiomyopathy: The Current Options, the Future, and the Challenges. J Clin Med, 11(8). doi:10.3390/jcm11082148