Abstract 18079: Targeted Use of Serum Free Light Chain Assay in the Diagnosis of Light Chain Amyloidosis in Patients With Heart Failure

Introduction: Light-chain amyloidosis (AL) is a rare disease with a prevalence of 8-10/million patient years. Cardiac AL is associated with poor prognosis if left untreated and its true prevalence is likely underestimated. The serum free light chain assay (FLC) is recommended as a diagnostic test when AL is suspected, but the utility of a screening FLC assay is unknown. Hypothesis: In patients with undifferentiated heart failure, targeted use of FLC assay may improve the diagnosis of AL. Methods: We studied consecutive new patients referred to the Heart Failure Clinic who had a routine screening FLC assay within 7 days of the initial visit at Mayo Clinic from January 2011 to December 2015. A FLC ratio between 0.26 and 1.65 was considered normal. Results: Of the total 1173 patients with heart failure and a screening FLC (mean age 64 ± 14 years), 207 patients had an abnormal FLC ratio (median [IQR]: 1.9 [1.7-2.3]). Patients with an abnormal FLC ratio were older, had higher left ventricular mass index and es...