Takotsubo Cardiomyopathy During Anti-HER2 Therapy for Metastatic Breast Cancer.

Human epidermal growth factor receptor 2 (HER2)-targeted antibodies, including pertuzumab and trastuzumab, improve overall survival and progression-free survival among women with HER2-positive metastatic breast cancer, but grade ≥3 cardiotoxicity occurs in approximately 8% of cases. Here we report a case of Takotsubo cardiomyopathy associated with the use of dual anti-HER2 therapy in a 63-year-old woman who presented to the emergency department with an 8- to 10-hour history of progressive dyspnea after completing her third cycle of pertuzumab plus trastuzumab in addition to nab-paclitaxel chemotherapy. To our knowledge, this patient represents the first reported case of Takotsubo cardiomyopathy associated with pertuzumab plus trastuzumab combination therapy in the literature.