Myocarditis incidence and hospital mortality from 2007 to 2022: insights from a nationwide registry.

Objectives: To investigate the burden of disease of myocarditis in Germany and identify similarities and differences in myocarditis with or without COVID-19.

Methods: All patients hospitalized with myocarditis in Germany were included in this nationwide retrospective analysis. Data were retrieved from the Federal Statistical Office of Germany (DESTATIS) for the years from 2007 to 2022. The primary endpoint was hospital mortality.

Results: A total of 88,159 patients hospitalized with myocarditis were analyzed. Annual cases increased from 5100 in 2007 to 6593 in 2022 (p < 0.001 for trend) with higher incidence during winter months. Incidence per 100,000 inhabitants was 6.2 in 2007 rising to 7.8 in 2022 (p < 0.001 for trend). Hospital mortality remained constant at an average of 2.44% (p = 0.164 for trend). From 2020 to 2022, 1547/16,229 (9.53%) patients were hospitalized with both, myocarditis and COVID-19 (incidence 0.62/100,000 inhabitants and 180/100,000 hospitalizations with COVID-19). These patients differed significantly in most patient characteristics and had a higher rate of hospital mortality compared to myocarditis without COVID-19 (12.54% vs. 2.26%, respectively, p < 0.001).

Conclusions: Myocarditis hospitalizations were slowly rising over the past 16 years with hospital mortality remaining unchanged. Incidence of hospitalizations with combined myocarditis and COVID-19 was low, but hospital mortality was high.