Increased Mortality After Hospitalization Due to Myocarditis - a Nationwide Register-Based Follow-Up Study

Research output: Contribution to journalConference abstract in journalCommunication


Introduction: Patients with myocarditis have variable prognosis. Large population-based studies are required for further clarification. In this case cohort study, the aim was to determine the mortality rate among people affected by myocarditis compared to age- and sex-matched population controls.

Methods: Nationwide healthcare registries were used to identify patients who were hospitalized and diagnosed with myocarditis between 1999-2015 in Denmark. Myocarditis patients were matched 1:5 to population controls, using birth year, sex and calendar month of the myocarditis event. Two-year all-cause mortality was reported using Kaplan-Meier estimates and shared Frailty Cox regression, with hazard ratios (HRs) and 95% confidence intervals (CI). Due to a steep mortality rate in the first month of follow-up, where the proportional hazards assumption was violated, we used a Split function to report HRs for after one month to two-year follow-up.

Results: Of 15,532 subjects enrolled, 2,589 were diagnosed with myocarditis and 12,945 were controls. The median age was 48 in both groups. Relative to controls, myocarditis patients had higher cardiac and non-cardiac comorbidity. The crude 2-year mortality was 13.7% (95% CI 12.42-15.08) in the myocarditis group (Figure 1), compared to 3.31% (95% CI 3.00-3.61) among controls, with a crude HR of 3.23 (95% CI 2.77-3.78). The corresponding HR, adjusted for age, sex and comorbidities was 2.83 (95% CI 2.39-3.36). When excluding preexisting comorbidities, 2-year all-cause mortality was 5.6% for myocarditis patients (95% CI 4.5-6.8) vs. 1.7% for controls (95% CI 1.5-1.9).

Conclusions: Patients with myocarditis have significantly higher mortality relative to age- and sex- matched population controls. Our results suggest myocarditis patients should be actively investigated and treated with plans for follow-up. Our findings suggest that the prognosis among patients with myocarditis have a poor prognosis, even when adjusted for comorbidities. The most deaths occur during the first month.
Translated title of the contributionØget mortalitet efter hospitalisering med myocarditis - et nationelt register-baseret follow-up studie
Original languageEnglish
Article numberAbstract 16197
Issue numberSuppl. 1
Number of pages1
Publication statusPublished - 5 Nov 2018
EventScientific Sessions of the American Heart Association, AHA - Chicago, Illinois, United States
Duration: 10 Nov 201812 Nov 2018


ConferenceScientific Sessions of the American Heart Association, AHA
Country/TerritoryUnited States
CityChicago, Illinois

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