Functional improvement measured by the six-minute walk test after chemotherapy in cardiac AL amyloidosis.

e19539 Background: Light chain amyloidosis (AL) is characterized by the accumulation of misfolded proteins that deposit in tissue causing multisystem organ dysfunction. Current treatments target plasma cells which produce pathogenic proteins. Development of amyloid protein directed monoclonal antibody therapy has led to increased need for objective measurements of clinical response. The 6 minute walk test (6MWT) has been used to monitor disease severity in clinical trials of heart failure. We hypothesized that improvement in 6MWT would correlate with improvement of cardiac biomarkers in AL patients. Methods: This was a retrospective analysis of 22 AL patients, 20 of which had definitive cardiac involvement, who completed 6MWT at diagnosis and at the end of planned initial chemotherapy. Additional cardiac assessments included NYHA class, BNP, troponin I and left ventricular ejection fraction (LV EF). Results: The majority (95%) received bortezomib-based initial chemotherapy and 59% (n = 13) underwent autol...