Reply to Letter to the Editor Regarding: "Myocarditis and Cardiac Complications Associated With COVID-19 and mRNA Vaccination".

To the Editor,

We thank Lampejo and Durkin for their interest in our recent publication, Myocarditis and Cardiac Complications Associated With COVID-19 and mRNA Vaccination: A Pragmatic Narrative Review to Guide Clinical Practice [1], and for their letter regarding the use of non-steroidal anti-inflammatory drugs (NSAIDs) in these clinical settings.

The management of COVID-19 and the complications of specific organ involvement is a rapidly expanding area of medicine, and there are limited data on the treatment of COVID-19 and mRNA vaccination-related myocarditis. In general, the use of NSAIDs in myocarditis is not recommended [2], based on experimental data from seminal animal studies indicating possible harm in viral aetiologies of myocarditis. Furthermore, NSAIDs are generally discouraged in acute or chronic cases of heart failure [3]. Though widely used in cases of isolated pericarditis, human safety data of NSAIDs in myocarditis and myopericarditis is limited to small retrospective audits [4,5], and robust data related specifically to COVID-19 is absent. Importantly, NSAIDs remain first-line therapy in pericarditis [6]. However, we agree with Lampejo and Durkin that, consistent with guideline recommendations for myocarditis and pericarditis [2,6], the use of NSAIDs should be carefully considered in cases related to COVID-19 or presentation associated with mRNA vaccination.