Mapping the patient pathway for ICI cardiac toxicities: a single-centre case series with clinical practice insights.

Immune checkpoint inhibitors (ICIs) have revolutionised cancer care, but can cause serious cardiac immune-related adverse events (irAEs), particularly myocarditis, which carries up to 50% mortality. This study explores patient pathways to improve early recognition and management of ICI myocarditis in acute settings. This was a retrospective, single-centre case series from a UK tertiary hospital with a specialist cardio-oncology multi-disciplinary team (MDT). Ten patients referred to the cardio-oncology MDT between March and August 2024 were included if diagnosed with myocarditis, pericarditis, or arrhythmias linked to ICI treatment. Clinical pathways were described using structured vignettes. Seven patients had myocarditis, two pericarditis, and one bradyarrhythmia. Fatigue (57%) was the most common presenting symptom in myocarditis. Echocardiography was unremarkable in 86% of cases, while cardiac magnetic resonance imaging (MRI) confirmed myocarditis in 57%. N-terminal pro-B-type natriuretic protein (NT-proBNP) rose 17-fold from baseline compared with a four-fold rise in troponin T. Early MDT referral facilitated prompt diagnosis and treatment, while delayed recognition was associated with worse outcomes. This case series highlights the importance of early MDT involvement, and the utility of additional cardiac biomarkers, such as NT-proBNP. It provides practical guidance to improve the acute care pathway for patients developing ICI-associated cardiac toxicities.