Advances in the Treatment of Cardiac Amyloidosis

Abstract

Cardiac amyloidosis is associated with a high mortality rate, a long delay between the first signs and the diagnosis but a short interval between diagnosis and death. This scenario has changed recently due to improved disease awareness among doctors and significant progress in diagnosis thanks to multimodal imaging and a multidisciplinary approach. Therefore, during the last few years, we have had access to specific therapies for those patients. Those therapies are quite different depending on the type of amyloidosis, but there has been real progress. Systemic light chain amyloidosis (AL) with cardiac involvement is the most common form of cardiac amyloidosis. The severity of heart disease dictates the prognosis in AL amyloidosis. Advances in chemotherapy and immunotherapy that suppress light chain production have improved the outcomes. These recent improvements in survival rates have enabled therapies such as implanted cardiac defibrillators and heart transplantation that were usually not indicated for patients with advanced light chain amyloid cardiomyopathy to now be applied in selected patients. For transthyretin amyloidosis (ATTR), the second most common form of amyloidosis with cardiac involvement, there is also significant progress in treatment. Until recently, we had no specific therapy for ATTR cardiomyopathy (ATTR-CM), though now disease-modifying therapies are available. Therapies that stabilize transthyretin, such as tafamidis, have been shown to improve outcomes for patients with ATTR-CM. Modern treatments that stop the synthesis of TTR through gene silencing, such as patisiran and inotersen, have shown positive results for patients with TTR amyloidosis. Significant progress has been made in the treatment of amyloid cardiomyopathy, and hopefully, we will see even more progress with the spread of those treatments. We now can be optimistic about patients with this disease.

Keywords: Amyloid; Amyloidosis; Heart failure; Light chain; Restrictive cardiomyopathy; Transthyretin.

Fig. 1

Treatment of cardiac amyloidosis. The management of patients with CA includes a comprehensive approach to administer supportive care as well as the specific treatment regarding the subtype of amyloidosis. The specific treatment for CA interrupts specific steps of amyloidogenesis, such as light chain or transthyretin protein synthesis, formation of amyloidogenic intermediates, or amyloid fibril aggregation. Others try to remove amyloid deposits in the tissue. *The utilization of traditional HF treatment including beta-blockers, ACE inhibitors, or angiotensin-receptor blockers appears to be less effective in these patients and should not be used routinely and perhaps be avoided in selected individuals **Anticoagulation is recommended in all patients with AF and cardiac amyloidosis, and the CHADS-VASC does not apply to that decision. Likewise, anticoagulation should be considered even in patients with sinus rhythm and enlarged atrium due to a high risk of left atrial thrombus promoting atrial dilatation. † Loop diuretics are recommended for fluid overload management. Have caution to avoid preload reduction and hypotension. § There are no current guidelines for the indication or optimal timing of prophylactic pacemaker implantation. # LVAD is feasible in very selected patients. ¶ The role of ICD in cardiac amyloidosis is not well established, and there are few data about CRT. mRNA micro RNA, TTR transthyretin, LC light chain, IG immunoglobulin, ICD implantable cardio defibrillator, CRT cardiac resynchronization therapy, AF atrial fibrillation.