Rassaf, Tienush

Importance The introduction of immune checkpoint inhibitor (ICI) therapy has improved cancer outcomes but at the cost of adverse events, mainly related to the immune system. Cardiovascular (CV) toxic effects, and especially myocarditis, are of particular concern and are the subject of this position statement by the International Cardio-Oncology Society with representation of experts from oncology, hematology, and cardiology. Observations CV toxic effects of ICI therapies include inflammation-associated diseases, such as myocarditis, pericarditis, and vasculitis, as well as the aggravation of chronic inflammatory conditions, such as atherosclerosis with acute ischemic complications (myocardial infarction and stroke). Patients taking ICI therapies can also develop cardiac dysfunction, stress-induced cardiomyopathy (Takotsubo or apical ballooning syndrome), and heart failure without inflammatory cell infiltration of the myocardium. Atrial and ventricular arrhythmias can emerge in the setting of a systemic inflammatory milieu, myocarditis, or ischemia. Of all potential CV adverse effects, myocarditis remains of highest concern, although fatality rates have declined over time with a broadening spectrum of presentations ranging from troponin elevation of uncertain significance to smoldering, nonsevere, and severe or fulminant myocarditis. Conclusions and Relevance Concerns for myocarditis continue to dominate the spectrum of CV toxic effects in patients receiving ICI therapy. Recommendations for management vary according to severity. Multidisciplinary collaborations remain key for managing acute toxic effects and future cancer treatment decisions, including ICI rechallenge. Ischemic heart disease constitutes the main differential diagnosis in these patients, while pericarditis can be concomitantly present, and atrial and ventricular arrhythmias can also complicate the clinical picture. Several gaps in knowledge are identified and require further research.

ABSTRACT The advent of immunological therapies has revolutionized the treatment of solid and haematological cancers over the last decade. Licensed therapies which activate the immune system to target cancer cells can be broadly divided into two classes. The first class are antibodies that inhibit immune checkpoint signalling, known as immune checkpoint inhibitors (ICIs). The second class are cell-based immune therapies including chimeric antigen receptor T lymphocyte (CAR-T) cell therapies, natural killer (NK) cell therapies, and tumour infiltrating lymphocyte (TIL) therapies. The clinical efficacy of all these treatments generally outweighs the risks, but there is a high rate of immune-related adverse events (irAEs), which are often unpredictable in timing with clinical sequalae ranging from mild (e.g. rash) to severe or even fatal (e.g. myocarditis, cytokine release syndrome) and reversible to permanent (e.g. endocrinopathies).The mechanisms underpinning irAE pathology vary across different irAE complications and syndromes, reflecting the broad clinical phenotypes observed and the variability of different individual immune responses, and are poorly understood overall. Immune-related cardiovascular toxicities have emerged, and our understanding has evolved from focussing initially on rare but fatal ICI-related myocarditis with cardiogenic shock to more common complications including less severe ICI-related myocarditis, pericarditis, arrhythmias, including conduction system disease and heart block, non-inflammatory heart failure, takotsubo syndrome and coronary artery disease. In this scientific statement on the cardiovascular toxicities of immune therapies for cancer, we summarize the pathophysiology, epidemiology, diagnosis, and management of ICI, CAR-T, NK, and TIL therapies. We also highlight gaps in the literature and where future research should focus.