Case Report: Lymphohistiocytic Myocarditis With Severe Cardiogenic Shock Requiring Mechanical Cardiocirculatory Support in Multisystem Inflammatory Syndrome Following SARS-CoV-2 Infection

Abstract

Multisystem Inflammatory Syndrome (MIS) is a novel hyperinflammatory syndrome associated with SARS-CoV-2 infection. It predominantly affects children (MIS-C) a few weeks after a usually asymptomatic SARS-CoV-2 infection and is only rarely seen in adults above 21 years (MIS-A). Only scarce data on histological findings in both pediatric and adult patients has been published so far. An 18-year-old male patient was admitted to hospital in a febrile state, which progressed to severe cardiogenic shock and multi-organ failure requiring extracorporeal life support. Myocardial biopsy revealed small vessel-associated immune cell infiltrates. Diagnosis of MIS-C was made after ruling out all potential differential diagnosis. Use of immunosuppressive treatment with steroids, interleukin-1 blockade and high-dose intravenous immunoglobulins resulted in the patient's full recovery. Multisystem Inflammatory Syndrome (MIS) is a new differential diagnosis of cardiac dysfunction in pediatric and adult patients. The lack of myocardial necrosis differentiates the disease from other viral myocarditis and offers an explanation for the fast response to immunomodulatory therapy and the favorable prognosis. The preceding SARS-CoV-2 infection might only have been mildly symptomatic or even asymptomatic.

Keywords: COVID-19; Impella®; MIS-C; Multisystem Inflammatory Syndrome in children; V-A ECMO; myocardial biopsy.

Figure 1

Clinical and treatment parameters of the patient during the 1st month after hospital admission. (A–H) show the time course of different laboratory parameters during the first 30 days following hospital admission. (I) displays a timeline of the different clinical parameters and specific therapy during the first 30 days.

Figure 2

Histopathology and immunohistochemistry of the patient's endomyocardial biopsy. Serial tissue sections of paraffin-embedded endomyocardial biopsies reveal perivascular fibrosis in absence of myocyte necrosis [Masson Trichrome (A) and HE (B) stainings, see circle] and severe infiltration of CD68+ macrophages (C) and CD3+ T cells (D) primarily around intracardiac small vessels (see circle, magnification x200). HE, hematoxylin-eosin; CD, cluster of differentiation.