Longer-Term Survivors of Light Chain Cardiac Amyloidosis

Abstract

Introduction Heart failure (HF) due to light chain (AL) cardiac amyloidosis (CA) is often considered to have a bleak prognosis with a median untreated survival of less than 6 months. A prognostic staging system has been developed by the Mayo Clinic utilizing NT-proBNP, troponin T, and the difference in free light chains (dFLC). Median survival of the two most advanced stages are 14 months for stage III, and 5.8 months for Stage IV. Advances in anti-plasma cell therapies have improved patient survival, most notably combination therapy using proteasome inhibitors (PI). We describe patients who presented with AL-CA at our institution who have survived for at least 3 years. Methods This is a retrospective review of patients with AL-CA seen between July 1997 and March 2016 at the Cleveland Clinic. Diagnosis of AL-CA was established via endomyocardial biopsy or extracardiac biopsy plus cardiac imaging in addition to evaluation with cardiac biomarkers. Results Of 303 patients with AL-CA, 82 (27%) survived for 3 years or longer. Average age at diagnosis for this cohort was 62 ±11 years and 61% of patients were male. In patients with available testing for Mayo staging (n = 45), 5 were Stage I, 12 were Stage II, 19 were Stage III, and 9 were Stage IV. 22 patients experienced exceptionally remarkable long-term survival (greater than 94 months). These long-term survivors tended to be younger, with an average age of 58 ±11 years, and 68% had multi-organ involvement of AL. Conclusions AL-CA is an aggressive disease that requires early diagnosis and treatment. More than one quarter of our patient population have a survival greater than 3 years. Of the 82-patient cohort who had survival greater than 3 years, two-thirds of patients who had data available for staging (28/45) presented with advanced Stage III or IV disease. 22 patients (7% of the overall cohort) survived nearly 8 years or more. Patients with AL-CA should be promptly treated with the help of an experienced multidisciplinary team using appropriately selected regimens, as this experience demonstrates that long-term survival can be achieved even for patients who present with more advanced disease.