Light-chain cardiac amyloidosis: a case report of extraordinary sustained pathological response to cyclophosphamide, bortezomib, and dexamethasone combined therapy.

Background: Heart involvement represents the most ominous prognostic factor in light-chain amyloidosis (AL), often foreclosing curative therapies such as high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). Heart transplantation (HTx) may be considered before ASCT in rigorously selected cases of advanced AL cardiac amyloidosis (CA). In ASCT-ineligible patients, chemotherapy with cyclophosphamide, bortezomib, and dexamethasone combined (CyBorD) regimen, even at low-dose, is feasible and effective in obtaining hematological and organ response. Case Summary: A previously healthy 50-year-old woman presented with severely symptomatic new-onset heart with preserved ejection fraction, significant cardiac hypertrophy, and an 'apical sparing' pattern. Bone marrow and abdominal fat biopsy revealed AL amyloidosis due to a smouldering micromolecular λ-type myeloma with severe cardiac involvement, and the patient was judged a good candidate to HTx followed by ASCT. Despite fragile conditions, she tolerated a full course of low-dose combination therapy with bortezomib and was withdrawn from HTx list because of unexpected persistent complete hematologic response and major cardiac improvement. Disease remission was achieved in the long term (>3 years). Discussion: We report a case of exceptional persistent hematologic and cardiac response after CyBorD therapy in a patient with advanced AL-CA who left the transplantation lists (both HTx and ASCT). In ASCT-ineligible patients, chemotherapy with CyBorD regimen, even at low-dose, can lead to durable remission of the disease with excellent cardiac response.