Concurrent Transthyretin Cardiac Amyloidosis and Light Chain Amyloidosis of the Foregut

Abstract

Introduction Transthyretin (TTR) cardiac amyloidosis is an underrecognized cause of cardiomyopathy in adultss, most commonly causing HFpEF. Herein we describe a patient with evidence of concurrent TTR cardiac amyloidosis and amyloid light-chain (AL) amyloidosis of the foregut. Case presentation A 70-year-old male with history of hypertension, peripheral neuropathy, lumbar spinal stenosis presented in January 2018 with abdominal pain and melena. Laboratory testing was significant for iron deficiency anemia. He underwent EGD and was found to have AL amyloidosis on gastric and duodenal biopsy. Serum protein electrophoresis showed paraprotein of 0.1 g/dL, and bone marrow aspirate showed 9% plasma cells. Skeletal survey showed absence of lytic lesions. TTE showed LV hypertrophy with LVEF 55% and global longitudinal strain at -19.4%. Systemic therapy with three cycles of Cyclophosphamide, Bortezomib, and dexamethasone (CyBorD) was planned, but he did not complete the third cycle due to insurance issues. In May 2019, he presented with hematemesis. Upper endoscopy showed thickened gastric and duodenal mucosa with active bleeding. Hemostasis was achieved after epinephrine injection and clipping. Troponin I was elevated at 0.2 ng/mL. TTE revealed LVEF 50%, grade I diastolic dysfunction, and abnormal global longitudinal strain at -11.5%. He was restarted on four cycles of CyBorD from June to October 2019. In September 2019, stress echocardiography showed worsening LVEF of 33% without evidence of ischemia. He did not endorse any heart failure symptoms. However, he was not verythat physically active. He had repeat EGD in November 2019 that showed persistent amyloid of the foregut on biopsy. In December 2019, Cardiac MRI showed no LGE. Technetium Pyrophosphate imaging in January 2020 showed grade 3 cardiac uptake, and heart to contralateral chest ratio uptake of 1.54. Genetic testing was negative for hereditary ATTR. Decision-making Findings on Technetium Pyrophosphate scan were suggestive of TTR cardiac amyloidosis. He refused an endomyocardial biopsy. Given the worsening heart failure and highly positive technetium pyrophosphate scan, he was started on tafamidis for TTR amyloidosis. Conclusions TTR cardiac amyloidosis is an underrecognized cause of cardiomyopathy. Other signs and symptoms that can lead to investigation for the diagnosis of amyloidosis include neuropathy and lumbar spinal stenosis. Noninvasive testing features of TTR cardiac amyloidosis include diffuse subendocardial or transmural LGE on cardiac MRI, and grade 2/3 uptake or heart to contralateral chest ratio >1.5 on the more sensitive technetium pyrophosphate scan. Endomyocardial biopsy can be done if technetium pyrophosphate scan is equivocal or if symptoms remain highly suggestive of amyloidosis with prior negative testing. It is also important to exclude AL cardiac amyloidosis as the treatment is different. Herein we described a rare case of concurrent TTR cardiac amyloidosis and AL amyloidosis of the foregut.