TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Multisystem Inflammatory Syndrome is a rare condition characterized by fever and multisystem organ failure that presents in those with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We present a case of a 37-year-old man with multisystem inflammatory syndrome in adults (MIS-A) to portray this complication of SARS-CoV-2 infection. CASE PRESENTATION: A 37-year-old man with a prior medical history of obesity and mild COVID-19 infection one month prior to admission was evaluated for persistent headaches, fever, and myalgias. The patient presented with leukocytosis, elevated inflammatory markers, a positive COVD-19 PCR, and a chest x-ray that was negative for pulmonary disease. Once admitted, he developed hypotension due to cardiogenic shock with vasoplegia, and decompensated into multiorgan system failure requiring vasopressor and ventilatory support. Corticosteroids and antibiotics were started, and transthoracic echocardiogram (TTE) revealed an ejection fraction (EF) of 30% with global hypokinesis. The patient was transferred to a tertiary care center, where a follow up TTE revealed an EF of 20%, requiring ionotropic therapy and left ventricular mechanical support with an Impella. The patient's inflammatory markers continued to rise, with a D-Dimer greater than 20 ug/mL, lactate dehydrogenase greater than 4,000 U/L, and ferritin greater than 40,000 U/L, and progressed to acute renal failure. The patient underwent continuous veno-venous hemofiltration, plasma exchange, and tocilizumab, eventually requiring veno-arterial extracorporeal membrane oxygenation for further hemodynamic support. However, due to continued decompensation, the patient expired despite maximal mechanical and pharmacologic support. DISCUSSION: Multisystem inflammatory syndrome in adults (MIS-A) has been described as cardiogenic shock with elevated inflammatory markers in the setting of a positive SARS-CoV-2 test without severe respiratory illness(1). While SARS-CoV-2 infections have been known to cause myocarditis on initial presentation(2), such a significant cardiogenic and vasodilatory shock refractory to both mechanical and pharmacologic support 1-month post-infection is extremely rare in adults, especially in this acuity. However, this presentation has been documented in children (MIS-C) who have had prior SARS-CoV-2 infection (3) with multi-organ inflammation. Treatment is supportive, including the use of corticosteroids, tocilizumab, intravenous immunoglobulin, and circulatory support, but further research is necessary to determine the pathophysiology behind this inflammatory response. CONCLUSIONS: Multisystem inflammatory syndrome in adults is a rare and severe inflammatory complication for those post-SARS-CoV-2 infection. Further research needs to be completed to distinguish the pathophysiology behind this response to optimize treatment. REFERENCE #1: Morris SB, Schwartz NG, Patel P, et al. Case Series of Multisystem Inflammatory Syndrome in Adults Associated with SARS-CoV-2 Infection - United Kingdom and United States, March-August 2020. MMWR Morb Mortal Wkly Rep. 2020;69(40):1450-1456. Published 2020 Oct 9. doi:10.15585/mmwr.mm6940e1 REFERENCE #2: Siripanthong B, Nazarian S, Muser D, et al. Recognizing COVID-19-related myocarditis: The possible pathophysiology and proposed guideline for diagnosis and management. Heart Rhythm. 2020;17(9):1463-1471. doi:10.1016/j.hrthm.2020.05.001 REFERENCE #3: Abrams JY, Oster ME, Godfred-Cato SE, et al. Factors linked to SEVERE outcomes IN multisystem Inflammatory syndrome in children (MIS-C) in the USA: A retrospective surveillance study. The Lancet Child & Adolescent Health. 2021;5(5):323-331. doi:10.1016/s2352-4642(21)00050 DISCLOSURES: No relevant relationships by Wahaaj Khan, source=Web Response No relevant relationships by Pedro Mogrovejo, source=Web Response No relevant relationships by Christian von Gizycki, source=Web Response