SHOCK4: Utilizing Mechanical Circulatory Support and Immunomodulation for the Management of Fulminant Lymphocytic Myocarditis: Case Series

Abstract

Purpose: Five consecutive patients with biopsy-proven lymphocytic myocarditis (LM) presented to our medical center with cardiogenic shock (CS) requiring Mechanical Circulatory Support (MCS) and Immunomodulatory therapy. We present our experience and highlight the variability of presentation and management strategies. Methods: Five consecutive patients presented to our center between 3/1/2022 and 12/1/2022 with acute onset ventricular dysfunction and CS (Table). One had an out-of-hospital cardiac arrest. Due to the fulminant presentation and lack of typical risk factors, there was high clinical suspicion for myocarditis. One patient had positive influenza A testing. Results: All patients were managed acutely with VA-ECMO with or without left ventricular ventilation. All patients underwent an endomyocardial biopsy which showed virus-negative LM. Immunomodulatory therapy strategies varied among patients. Our initial approach was Methylprednisolone for 3 days and IVIG for all. Moreover, for those with a slower rate of recovery, or continued high inflammatory markers, plasmapharesis was utilized in addition to prolonged prednisone and/or azathioprine courses (Table). Of the five subjects, two had myocardial recovery, one developed chronic myocarditis, one developed chronic heart failure, and one required a durable LVAD. Conclusion: Lymphocytic myocarditis is a rare inflammatory disorder of the heart characterized by mononuclear cellular infiltrate and ventricular dysfunction. Fulminant myocarditis is characterized by CS or cardiac arrest. Prompt diagnosis is critical because the prognosis and recovery are better than with nonspecific histological findings or giant cell myocarditis (1,2). Our series and others have demonstrated MCS key role in decreasing mortality while treating the myocardial consequences of inflammatory injury (5-7). While viral infections are the most common cause found in 30-40% of cases (1,3,4), only one patient in our series had an influenza A infection, and none had positive viral testing on the biopsy. We found no consistent history of COVID-19 infection or vaccination among the patients. There is no consensus on the best strategy for immunomodulatory therapy, and more extensive studies with long-term outcomes are needed.