Checkpoint inhibitor myocarditis is a complication of the use of immunomodulatory antineoplastic drugs in which an autoimmune response against myocardial tissue antigens occurs.
We present the case of an 82-year-old patient with hypertension, type 2 diabetes, dyslipidaemia, and a history of smoking with no previous cardiac history, who is being followed up in the gastroenterology department after resection of a hepatocellular carcinoma and is currently undergoing immunotherapy (Durvalumab/Tremelimumab).
He attends a follow-up appointment after receiving the second cycle of Durvalumab. He is asymptomatic at the cardiovascular level, and laboratory tests reveal a marked elevation of troponins, with no notable alterations on echocardiography. Empirical treatment with megadoses of corticosteroids is initiated, and studies are completed by coronary angiography, which shows only mild stenosis in the right coronary artery, as well as cardiac MRI, which confirms the clinical suspicion of myocarditis with oedema in STIR sequence and patches of late enhancement.
Immune-mediated myocarditis is a condition whose incidence has been on the rise in recent years in relation to the increased use of checkpoint inhibitors (PD1, PDL1, and CTLA4). Although rare, given the high mortality rate, clinical suspicion is essential, as in most cases it is asymptomatic in the early stages, with only troponin elevations or non-specific ECG abnormalities being detected. Early treatment is essential, with corticosteroid boluses (1 g/day) being the first-line treatment of choice, which may be combined with other immunosuppressants in cases of poor response or corticosteroid dependence.