Eosinophilic Myocarditis With Rapid Progression to Cardiogenic Shock, Managed With Mechanical Support and High-Dose Corticosteroids

A 19-year-old woman with no significant medical history was admitted to the University of Vermont Medical Center with 3 weeks of abdominal pain, vomiting, and diarrhea, as well as 2 to 3 days of chest pain.Her only medication was oral contraceptives, which she had taken for the past 2 years.At presentation, her blood pressure was 97/78 mm Hg and heart rate 107 beats per minute and regular.Physical examination was remarkable for mild generalized pallor, diffuse abdominal tenderness, elevated jugular venous pressure, and a gallop rhythm.Laboratory results revealed a total white blood cell count count of 16.6 K/mm 3 (Reference, 4.0-10.4K/mm 3 ), absolute eosinophil count of 8.52 (Reference, 0.03-0.61K/mm 3 ), troponin I of 9.99 (Reference, <0.034 ng/mL), and IgE of 241 (Reference, <158 IU/ mL).Initial ECG revealed ST-segment elevation in leads I, II, III, aVF, and V 4 through V 6 , ST depression in leads V 1 through V 3 , and mild PR-segment depression (Figure 1A).A chest computed tomographic scan was negative for pulmonary embolism.Within a few hours of admission, the patient's condition deteriorated rapidly, with development of worsening hypotension and tachycardia (blood pressure, 86/42 mm Hg; heart rate 134 beats per minute).Echocardiography revealed a trivial pericardial effusion, left ventricular (LV) ejection fraction of 30% to 35% with diffuse hypokinesis and marked thickening of the septum and posterior wall consistent with intramyocardial edema, and reduced LV cavity size (Figure 2A and 2B).Because of worsening hemodynamics, the patient was emergently transferred to the Tufts Medical Center for consideration of advanced therapies.After arrival, repeat echocardiography (≈8 hours after initial echocardiogram) showed further biventricular thickening and dysfunction (LV ejection fraction 5%-10%; Figure 2C and 2D, note right ventricle involvement in panel D; Movies I and II in the Data Supplement).Right heart catheterization revealed mean right atrial pressure of 20 mm Hg, pulmonary artery pressure of 31/25 mm Hg, and a mixed venous oxygen saturation of 41%.She was begun on inotropic support with milrinone and dopamine and emergently underwent Impella CP implantation.Soon after transfer, empirical methylprednisolone of 1 g IV was administered.Endomyocardial biopsy performed the following morning showed evidence of eosinophilic myocarditis (EM; Figure 3).Methylprednisolone 1 g daily was administered for 3 days, with near-complete resolution of peripheral eosinophilia.Within 4 days, hemodynamic support was discontinued, and the patient was transitioned to prednisone 50 mg PO daily and metoprolol succinate of 50 mg, losartan of 12.5 mg, and spironolactone of 12.5 mg, all PO daily.On hospital day 6, a repeat echocardiogram revealed marked improvement in cardiac function, with LV ejection fraction of 45%.Ten days after her initial presentation, LV function had fully normalized (ejection fraction 60%-65%) with normal LV chamber size and wall thickness (Figure 2E and 2F; Movies III and IV in the Data Supplement).Repeat biomarker measurements 2 weeks after presentation revealed troponin I of 0.443 and an eosinophil count of 0.06, with normalization of ST segments on ECG (Figure 1B).