Abstract 10064: Tracking Multi-Organ Treatment Response in Systemic Al-Amyloidosis With Cardiac Magnetic Resonance Derived Extracellular Volume Mapping

Abstract

Introduction: Systemic light-chain (AL) amyloidosis commonly involves the liver, spleen and heart. Cardiac magnetic resonance (CMR) with extracellular volume (ECV) mapping has demonstrated accuracy in measuring hepatic, splenic and cardiac amyloid infiltration. We sought to assess multi-organ response to treatment using CMR derived ECV mapping. Methods: We identified 351 patients who underwent baseline SAP scintigraphy and CMR at diagnosis, of which 171 had follow-up imaging. Results: Liver and spleen ECV correlated with amyloid load assessed by SAP scintigraphy (R=0.751, P<0.001; R=0.765, P<0.001), with serial measurements accurately tracking treatment response. ECV regression was observed at 6-months in those with a good haematological response (liver=15%, spleen=15%, heart=5%). The remaining patients with a good response had stable liver and spleen ECVs, but 20% had cardiac progression. Baseline liver (HR=1.03, 95%CI[1.01-1.05], P<0.001) and myocardial ECV (HR=1.05, 95CI%[1.03-1.07], P<0.001) independently predict mortality. Change in liver (HR=1.06,95%CI[1.01-1.11], P=0.015) and myocardial ECV (HR=1.11, 95%CI[1.02-1.19], P=0.011) a 6-months independently predict mortality, while liver and cardiac regression at 12-months predict survival. Conclusions: Multi-organ ECV quantification accurately tracks treatment response, and demonstrates different rates of organ regression, with the liver and spleen regressing more rapidly than the heart. Liver and myocardial ECV at diagnosis and increases in ECV at 6-months independently predict mortality.