Association Between Myocarditis and Mortality in COVID-19 Patients in a Large Registry

OBJECTIVE: To present a large registry data assessing the association between myocarditis and mortality in patients with severe acute respiratory syndrome coronavirus 2 infection. PATIENTS AND METHODS: The researchers identified adult patients aged 18 to 90 years of age with coronavirus disease 2019 (COVID-19) diagnosis in the TriNetX (COVID-19 research network) database between January 20, 2020, and December 9, 2020. These patients were then divided into groups of those who had a positive myocarditis diagnosis and those who did not. The researchers compared all-cause mortality between propensity-matched pairs of patients in both groups. RESULTS: A total of 259,352 patients with COVID-19 diagnosis were included in the study. Of those patients, 383 (0.2%) had myocarditis diagnosis, whereas 258,969 (99.8%) did not have myocarditis diagnosis during their hospital stay. Patients were predominantly male in the myocarditis group (59.0% vs 45.0%, P<0.001). As to the propensity-matched cohorts, 383 of 383 were matched, and the all-cause mortality was 13.4 % vs 4.2% (P<0.001) at 30 days. A Kaplan-Meier survival analysis was also statistically significant (P<0.001) at 30 days. CONCLUSION: In a large multinational database of COVID-19 patients, we observed an association between myocarditis diagnosis and increased mortality. Further prospective studies are recommended to further assess myocarditis outcomes in COVID-19 patients and treatment options.