Osimertinib-induced cardiac failure with QT prolongation and torsade de pointes in a patient with advanced pulmonary adenocarcinoma.

Osimertinib-induced cardiotoxicity is a well-known but rare disorder. An 84-year-old woman was diagnosed with recurrence of lung adenocarcinoma showing an epidermal growth factor receptor mutation of exon 19 deletion, which was initially treated by curative-intent thoracic radiotherapy 4 years prior. She started taking osimertinib (80 mg/day). She had no history of heart disease and showed no signs of cardiac problems. However, 2 months later she presented with symptoms of cardiac failure and QT prolongation on electrocardiogram. Cardiac enzyme levels were not elevated and coronary computed tomography angiography showed no significant stenosis. On admission, sudden-onset torsade de pointes required electrocardioversion. Thus, drug-induced cardiac failure was strongly suspected and we stopped osimertinib therapy. Cardiac function and the electrocardiogram abnormality improved. To our knowledge, this is the third case of coincidence of cardiac failure and QT prolongation and the second case of sudden-onset torsade de pointes associated with osimertinib treatment. In our case, osimertinib-induced cardiac failure with QT prolongation was recovered by stopping the drug treatment. The potential for cardiotoxicity should be considered with osimertinib treatment.