[Third degree atrio-ventricular blockade during a myocarditis occurring under anti-PD1 : Case report and literature review]

Abstract

Introduction: Immune Checkpoint Inhibitor (ICI) therapy is now a standard of care in numerous cancers with very promising results. Nevertheless, adverse events, and especially immune-related adverse events (irAEs) not reported during clinical trials, are emerging and can be life-threatening.

Observation: We report here a teachable case of a 80 year-old man, of third-degree atrioventricular block consecutive to myocarditis associated with the administration of nivolumab (anti-PD1) monotherapy.

Conclusion: Myocarditis occurring during ICI treatment is a rare but potentially lethal event. Daily serum troponin level seems to predict ICI-related myocarditis but interpretation could be difficult in the context of associated myositis. Echocardiography and cardiac MRI are also useful but can remain negative. Electrocardiogram is a cornerstone of myocarditis diagnosis. In case of cardiac involvement, continuous heart rhythm monitoring should be performed in addition to the administration of high-dose corticosteroids therapy and the cessation of ICI therapy. Add-on treatments should be discussed with a well-trained multidisciplinary team.

Keywords: Effets indésirables auto-immuns; Immune checkpoint inhibitor; Immune-related adverse events; Inflammatory myopathy; Inhibiteur de point de contrôle immunitaire; Myocardite; Myocarditis; Myopathie inflammatoire.