Immunotherapy-mediated myocarditis and concurrent vasospastic angina in a patient with established ischaemic heart disease: a case report.

Background: Immunotherapy has become a pillar of modern oncological management but is associated with significant immunotherapy-related adverse events (IRAEs). While myocarditis is a prominent IRAE which clinicians are increasingly aware of, immunotherapy-related coronary vasospasm is far less appreciated and can be especially difficult to elucidate in pre-existing coronary artery disease. This case demonstrates the approach to diagnosis and management of multiple cardiovascular and non-cardiovascular IRAEs. Case summary: A 57-year-old male with a history of metastatic melanoma on combined immunotherapy and ischaemic heart disease with multiple previous percutaneous coronary interventions presented with typical chest pain and troponin rise. Differential diagnoses for this presentation included a non-ST elevation myocardial infarction, myocarditis, and coronary vasospasm. Coronary angiogram did not reveal any new significant obstructive coronary artery disease while cardiac MRI did not reveal any radiological features consistent with myocarditis. However, empirical treatment for IRAEs resulted in both clinical and biochemical improvement and ability to discharge the patient on steroids and coronary vasodilators, having been GTN-infusion dependent as an inpatient. Discussion: Cardiovascular IRAEs are important to be aware of when managing patients on immunotherapy and more than one IRAE can occur concurrently. Given the caveats of non-invasive imaging and invasive nature of endomyocardial biopsy, the clinical history is key in establishing these crucial diagnoses which will significantly impact ongoing oncological management.