Cardiotoxicity in cancer immune-checkpoint therapy: Mechanisms, clinical evidence, and management strategies

Immune-checkpoint inhibitors (ICIs), a unique antibody-based therapeutic strategy, have revolutionized the treatment landscape of solid and hematological cancers. Despite the proven benefits of ICIs, the cardiotoxicity from unspecific immune activation (uncommon but potentially fatal) is a continuing concern. Accumulating preclinical research has demonstrated that ICIs initiate inflammation in the myocardium, while clinically significant cardiotoxicity were reported in few patients receiving ICI therapy, probably due to the low incidence and unspecific symptoms. The subtle signs and symptoms (e.g., chest pain, dizziness, and dyspnea) were likely attributed to cancer and/or non-cardiac events by previous studies, thus limiting the understanding of the incidence, outcomes, risk factors, and management of ICI-related cardiotoxicity. The heterogeneous clinical presentation and complex diagnostic procedure further make it challenging to accurately identify ICI-related cardiac events in clinical trials. Therefore, ICI-related cardiotoxicity, whose incidence is probably underestimated, has not been well recognized. In this article, we provide an overview of potential mechanisms underlying ICI-related cardiotoxicity and review accumulating clinical evidence of ICI-related cardiotoxicity, with a focus on myocarditis. Moreover, we discuss possible strategies to manage ICI-related cardiotoxicity and highlight the importance of developing cardio-oncology.