Natural history and therapy of AL cardiac amyloidosis

Abstract

The natural history of immunoglobulin light chain associated amyloidosis (AL) is determined by the extent of cardiac involvement. Patients with cardiac AL and symptomatic heart failure have a median survival of approximately six months without successful treatment of the underlying plasma cell disorder The outcome in cardiac AL is determined by both the severity of cardiac involvement and the response to treatment. Staging systems using cardiac biomarkers, including NT- proBNP and troponin, have been found to be powerful predictors of prognosis and are used to guide treatment. Arrhythmias are common in cardiac AL and may lead to acute hemodynamic compromise. Sudden cardiac death, often due to pulseless electrical activity, is an important cause of early mortality. Supportive therapy for heart failure is usually limited to diuretics. Beta-blockers, ACE-inhibitors, and angiotensin receptor blockers are poorly tolerated in cardiac AL and should be avoided. Cardiac transplantation is controversial and reserved for highly selected patients with limited extracardiac involvement. The primary target of treatment in cardiac AL is obliteration of the plasma cell clone, using chemotherapy alone or combined with autologous stem cell transplantation. Despite the risk of early mortality, overall survival has improved with advances in disease modifying therapy. Earlier diagnosis and treatment of cardiac AL is crucial to improving survival.