Heart Failure in Relation to Tumor-Targeted Therapies and Immunotherapies

Tumor-targeted therapies such as trastuzumab have led to significant improvements in survival of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, these therapies have also been associated with significant left ventricular dysfunction. The incidence of trastuzumab-induced heart failure has decreased significantly since the initial reports, in large part due to improved screening, closer monitoring for early changes in left ventricular function, and a significant decrease in the concurrent administration of anthracyclines. The mechanism of trastuzumab cardiotoxicity is still not well understood, but current knowledge suggests that ErbB2 inhibition in cardiac myocytes plays a key role. In addition to trastuzumab and other HER2-targeted agents, vascular endothelial growth factor inhibitors, proteasome inhibitors, and immune checkpoint inhibitors are all additional classes of drugs used with great success in the treatment of solid tumors and hematologic malignancies. Yet these, too, have been associated with cardiac toxicity that ranges from a mild asymptomatic decrease in ejection fraction to fulminant myocarditis. In this review, we summarize the cardiotoxic effects of tumor-targeted and immunotherapies with a focus on HER2 antagonists.