Corticosteroids are often used to treat specific forms of acute myocarditis such as eosinophilic or giant cell infiltrations), according to a review article, but “this practice is based on anecdotal evidence, and randomized clinical trials of optimal therapeutic interventions for acute myocarditis are needed.”
“The most common causes of myocarditis are viruses, such as influenza and coronavirus; systemic autoimmune disorders, such as systemic lupus erythematosus; drugs, such as immune checkpoint inhibitors; and vaccines, including smallpox and mRNA COVID-19 vaccines,” the authors write. “Approximately 82% to 95% of adult patients with acute myocarditis present with chest pain, while 19% to 49% present with dyspnea, and 5% to 7% with syncope.”
Regarding prognosis and treatment, the review article states: “Approximately 75% of patients admitted with myocarditis have an uncomplicated course, with a mortality rate of approximately 0%. In contrast, acute myocarditis that is complicated by acute heart failure or ventricular arrhythmias is associated with a 12% rate of either in-hospital mortality or need for heart transplant. Approximately 2% to 9% of patients have hemodynamic instability, characterized by inability to maintain adequate end-organ perfusion, and require inotropic agents, or mechanical circulatory devices, such as extracorporeal life support, to facilitate functional recovery. These patients have an approximately 28% rate of mortality or heart transplant at 60 days. Immunosuppression (eg, corticosteroids) is appropriate for patients who have myocarditis characterized by eosinophilic or giant cell myocardial infiltrations or due to systemic autoimmune disorders. However, the specific immune cells that should be targeted to improve outcomes in patients with myocarditis remain unclear.”