Case 1: Myocarditis
An 84-year-old man receiving a chemoimmunotherapy regimen consisting of carboplatin, pemetrexed, and pembrolizumab for recurrent, stage IV lung adenocarcinoma developed grade 4 cardiomyopathy, as defined by the Common Terminology Criteria for Adverse Events (CTCAE) v5.0, during his treatment.8 He was treated for 2 cycles before he began experiencing an increase in liver enzymes.
The patient’s presentation was concerning for myocarditis, and he was quickly admitted to NMVAMC. Cardiac catheterization did not reveal any signs of coronary occlusive disease. Prednisone 1 mg/kg was administered immediately; however, given continued chest pain and volume overload, he was quickly transitioned to solumedrol 1000 mg IV daily. After the initiation of his treatment, the patient’s transaminitis began to resolve, and troponin levels began to decrease; however, his symptoms continued to worsen, and his troponin rose again. By the fourth day of hospitalization, the patient was treated with infliximab, a tumor necrosis factor-α inhibitor shown to reverse ICI-induced autoimmune inflammation, with only mild improvement of his symptoms. The patient’s condition continued to deteriorate, his troponin levels remained elevated, and his family decided to withhold additional treatment. The patient died shortly thereafter.
Discussion
Cardiotoxicity resulting from ICI therapy is far less common than the other potential severe toxicities associated with ICIs. Nevertheless, many cases of ICI-induced cardiac inflammation have been reported, and it has been widely established that patients treated with ICIs are generally at higher risk for acute coronary syndrome.9-11 Acute cardiotoxicity secondary to autoimmune destruction of cardiac tissue includes myocarditis, pericarditis, and vasculitis, which may manifest with symptoms of heart failure and/or arrhythmia. Grading of ICI-induced cardiomyopathy has been defined by both CTCAE and the American Society of Clinical Oncology (ASCO), with grade 4 representing moderate to severe clinical decompensation requiring IV medications in the setting of life-threatening conditions.
Review articles have described the treatment options for severe cases.7,12 As detailed in prior reports, once ICI-induced cardiomyopathy is suspected, urgent admission and immediate evaluation to rule out acute coronary syndrome should be undertaken. Given the potential for deterioration despite the occasional insidious onset, aggressive cardiac monitoring, and close follow-up to measure response to interventions should be undertaken.