CMR Parametric Mapping in Immune Checkpoint Inhibitor Myocarditis: Novel Noninvasive Tools in a Lethal Condition

Immune checkpoint inhibitor-induced myopericarditis

A woman in her 30s with a medical history of metastatic rectal adenocarcinoma, currently on pembrolizumab, which started a few weeks ago, was admitted for abdominal pain. During the hospital stay, she experienced sharp chest pain. Troponin was 1885 ng/mL which peaked at 7338 ng/mL. ECG was unremarkable. The echocardiogram showed an Ejection fraction (EF) of 55%-60% and basal-inferior wall hypokinesis. Left heart catheterisation showed no coronary abnormalities. Cardiac MRI showed a non-coronary area of focal T1 and T2 hyperintense signal and transmural delayed gadolinium enhancement in the mid-basal inferior/inferoseptal wall consistent with myocardial damage. Pericardium showed increased thickness and adhesions at the right ventricular outflow tract consistent with pericarditis. Steroid therapy was initiated, and a marked clinical response was achieved. Immune checkpoint inhibitor-induced myocarditis and pericarditis is a rare complication associated with a high mortality rate, if untreated. Diagnosis requires a multidisciplinary approach, and early detection is critical to preventing a fatal outcome.

Role of cardiac MRI in the diagnosis of immune checkpoint inhibitor-associated myocarditis

Immune Checkpoint Inhibitor (ICI)-induced cardiotoxicity is a rare immune-related adverse event (irAE) characterized by a high mortality rate. From a pathological point of view, this condition can result from a series of causes, including binding of ICIs to target molecules on non-lymphocytic cells, cross-reaction of T lymphocytes against tumor antigens with off-target tissues, generation of autoantibodies, and production of pro-inflammatory cytokines. The diagnosis of ICI-induced cardiotoxicity can be challenging, and cardiac magnetic resonance (CMR) represents the diagnostic tool of choice in clinically stable patients with suspected myocarditis. CMR is gaining a central role in diagnosis and monitoring of cardiovascular damage in cancer patients, and it is entering international cardiology and oncology guidelines. In this narrative review, we summarized the clinical aspects of ICI-associated myocarditis, highlighting its radiological aspects and proposing a novel algorithm for the use of CMR.

Fulminant myocarditis caused by immune checkpoint inhibitor: a case report and possible treatment inspiration

Immune checkpoint inhibitors (ICIs) have become a new hope for many patients with advanced cancer by blocking tumour immune evasion. However, with the widespread use of ICIs, immune-related adverse events (irAEs) have also been discovered and reported increasingly. Immune-related myocarditis, the most dangerous one of irAEs, still has high mortality in the context of the current treatment. We report the case of a 60-year-old female with fulminant myocarditis induced by ICIs, which caused her to experience frequent ventricular arrhythmias such as ventricular fibrillation and heart failure. She was successfully treated with current mainstream therapies for immune-related myocarditis and additional treatment of sacubitril-valsartan and dapagliflozin. The intriguing observation that the patient condition recovered relatively rapidly in this case shows a possible treatment inspiration, which may be helpful for treating ICIs-associated myocarditis and improving cancer patients' clinical prognosis.