Myocarditis mortality with and without COVID-19: insights from a national registry

Abstract

Background Myocarditis in context of a SARS-CoV-2 infection is vividly discussed in the literature. Real-world data however are sparse, and relevance of the myocarditis diagnosis to outcome in coronavirus disease (COVID-19) is unclear. Patients and methods Retrospective analysis of 75,304 patients hospitalized in Germany with myocarditis between 2007 and 2020 is reported by DESTATIS. Patients hospitalized between 01/2016 and 12/2019 served as reference cohort for the COVID-19 patients hospitalized in 2020. Results A total of 75,304 patients were hospitalized between 2007 and 2020 (age 42.5 years, 30.1% female, hospital mortality 2.4%). In the reference cohort, 24,474 patients (age 42.8 years, 29.5% female, hospital mortality 2.2%) were registered. In 2020, annual myocarditis hospitalizations dropped by 19.6% compared to reference (4921 vs. 6119 annual hospitalization), of which 443/4921 (9.0%) were connected to COVID-19. In 2020, hospital mortality of myocarditis in non-COVID-19 patients increased significantly compared to reference (2.9% vs. 2.2%, p = 0.008, OR 1.31, 95% CI 1.08–1.60). In COVID-19 myocarditis, hospital mortality was even higher compared to reference (13.5% vs. 2.2%, p < 0.001, OR 6.93, 95% CI 5.18–9.18). Conclusion The burden of patients with myocarditis and COVID-19 in 2020 was low. Hospital mortality was more than sixfold higher in patients with myocarditis and COVID-19 compared to those with myocarditis but without COVID-19. Graphical abstract

Incidence and risk factors of myocarditis in hospitalized patients with COVID‐19

“…Several studies showed that younger age, as well as male sex, are risk factors for the development of myocarditis in COVID-19. 13,14,18 In addition and in concordance with our findings, previously published literature also points to an interaction between other infections, such as pneumonia as well as multisystemic inflammatory COVID-19 infection and myocarditis. 14,52 This is an important finding since mortality in COVID-19 patients has been linked to a "cytokine storm" induced by the SARS-CoV-2.…”

“…The in‐hospital case‐fatality rate was 1.3‐fold higher in COVID‐19 patients with than without myocarditis. We identified a case‐fatality rate of 24.3% in patients with confirmed COVID‐19 diagnosis by laboratory test and myocarditis, which is lower than in the in‐hospital mortality rate of COVID‐19‐patients with myocarditis in the United States (31.5%), 45 but higher than the previously published 13.5% in the study of Bemtgen et al 18 (also examining the German nationwide inpatient cohort) but including in contrast to our analysis not only patients with confirmed COVID‐19 diagnosis by laboratory test (but also patients with suspicion of COVID‐19 and typical symptoms without definite confirmation of COVID‐19) as well as post‐COVID myocarditis 18 . The laboratory confirmation of COVID‐19 is an important criteria of this study and a key strength of our and the study of the US 45 .…”

“…Our study demonstrated that the highest absolute numbers of myocarditis cases were seen during spring (March/April) and in winter (November/December), along with the highest numbers of hospitalized COVID‐19 patients 5,18 and thus, following the seasonal variations of viral infections 18,27 . In this context, the highest relative numbers of myocarditis, in turn, were identified in the summer, suggesting that in summer was the risk of developing myocarditis at its maximum.…”

“…9 The in-hospital case-fatality rate was 1. 18 The laboratory confirmation of COVID-19 is an important criteria of this study and a key strength of our and the study of the US. 45 Our results were supported by an analysis of the NIS from the US, revealing that in-hospital mortality of COVID-19 patients with myocarditis was higher in comparison to those COVID-19 patients without myocarditis (OR: 1.59 [95% CI: 1.27−1.90]) 45 and that in-hospital mortality of patients with COVID-19 and myocarditis was higher compared to those patients with myocarditis, but without COVID-19 infection (30.7% vs.…”

“…Still, in-hospital mortality was more than sixfold higher in patients with myocarditis and COVID-19 compared to those with myocarditis but without COVID-19. 18 In contrast, the Center of Disease Control (CDC) reported a 42.3% increase in myocarditis in hospitalized patients during the year 2020 in comparison to 2019, analyzing the US hospital-based administrative database of healthcare from more than 900 hospitals during March 2020 and January 2021. 14 Data for Europe comparing COVID-19 patients with and without myocarditis are sparse.…”