Abstract 18997: Management of Immune Checkpoint Inhibitor Mediated Myocarditis

Abstract

Clinical Presentation: A 52-year-old female with metastatic Stage IVB (T4N3M1c) lung adenocarcinoma presented with worsening dyspnea. She had just completed her 3 rd round of carboplatin/pemetrexed/pembrolizumab/MK-5890 chemotherapy. Upon examination she was noted to be hypertensive and tachycardic with an elevated high-sensitivity troponin T. ECG showed sinus tachycardia, left axis deviation, and flattened T waves in lead V5 and V6. In the ED, she subsequently developed supraventricular tachycardia and was admitted to the ICU. TTE demonstrated moderately reduced EF of 30-35%. TTE also identified hypokinesis in the basal to mid anterior and lateral walls and apical akinesis. Initial CMR showed an EF of 31% with akinesis of the mid and apical anterior, septal and inferior wall. Given the clinical and imaging findings, she was diagnosed with myopericarditis secondary to pembrolizumab and started on 1 mg/kg methylprednisolone taper for 60 days. Repeat CMR after completion of steroid taper showed evidence of weighted T2 edema in myocardium and pericardium. Late gadolinium enhancement (LGE) in inferior and lateral epicardium and adjacent pericardium as well as patchy LGE throughout the myocardium with significant EF improvement (57%) (Figure 1A-B). In our patient, multi-modality imaging was used to confirm the diagnosis and monitor treatment response. Discussion: Immune checkpoint inhibitors (ICI) are a novel class of immunotherapies used in certain malignancies. Initial treatment of myocarditis consists of cessation of further ICI and administration of corticosteroids. Additionally, symptomatic myocarditis treatment should be started. Reinitiating ICI therapy should ultimately be done with shared decision making.