Transthyretin Cardiac Amyloidosis Mimicking Immune Checkpoint-Induced Myocarditis in a Patient Treated with Atezolizumab and Bevacizumab for Advanced Hepatocellular Carcinoma: A Case Report.

Checkpoint kinase inhibitors are increasingly used in oncology. The combination of atezolizumab and bevacizumab is currently the recommended first-line treatment for advanced hepatocellular carcinoma. Cardiac toxicities of immunotherapies are rare, but can lead to discontinuation of treatment. Transthyretin cardiac amyloidosis is a rare condition, but its incidence is probably underestimated. Its symptoms may suggest immunotherapy-induced myocarditis. When immune-mediated myocarditis is suspected, a thorough cardiac evaluation is necessary to confirm or refute the diagnosis of myocarditis and to avoid unnecessary interruption of immunotherapy. Cardiac magnetic resonance imaging may raise suspicion of transthyretin cardiac amyloidosis, the diagnosis being confirmed by technetium pyrophosphate bone scintigraphy.