Sex-related differences in myocarditis: insights from a contemporary cohort
J Conde Goncalves, L Alves, B Viana, T Branco, E Figueiredo, E Oliveira, B Cruz, M Paiva, M VasconcelosAbstract
Background
Myocarditis is an inflammatory cardiac disease with a broad clinical spectrum. Sex-related differences in immune response and myocardial injury may influence clinical presentation, imaging patterns and outcomes, yet these differences remain insufficiently characterized in contemporary cohorts.
Purpose
To describe sex-based differences in clinical presentation, etiology, electrocardiographic and imaging findings and long-term outcomes in patients with myocarditis.
Methods
We performed a retrospective observational study including consecutive patients admitted with myocarditis to a tertiary referral center between January 2016 and November 2025. Data were extracted from electronic medical records. Categorical variables were compared using χ² or Fisher’s exact test and continuous variables using the Mann–Whitney U test, as appropriate.
Results
A total of 138 patients were included, of whom 81.2% were male. Female patients were older than males (median age 32.5 vs 27.5 years; p = 0.042). Myocarditis etiology differed significantly by sex (p = 0.032), with viral etiology predominating in men and autoimmune myocarditis being more frequent among women. Concomitant pericarditis was more common in male patients (p = 0.021).Initial ECG findings differed between sexes (p = 0.016), with ST-segment elevation occurring more frequently in men, whereas women more often presented with a normal ECG or ST-segment depression.Cardiac magnetic resonance was performed in 88.4% of patients. Men exhibited a greater extent of myocardial oedema, with a higher median number of involved segments (3 vs 2; p = 0.024). Late gadolinium enhancement was more frequent in men than women (p = 0.023). Left ventricular ejection fraction was typically preserved and did not differ between sexes (p = 0.974).During a median follow-up of 37 months, women were more frequently symptomatic compared with men (p = 0.013). No significant sex-related differences were observed in follow-up CMR findings (persistent oedema, p = 0.466; late gadolinium enhancement, p = 0.142), cardiovascular rehospitalization (p = 0.759) or myocarditis recurrence (p = 0.651). Mortality was low, with two deaths during follow-up, one in each sex.
Conclusion
In this cohort, myocarditis demonstrated significant sex-related differences in etiology, electrocardiographic presentation, myocardial inflammatory burden and symptom persistence during follow-up. These findings likely reflect sex-specific immune and inflammatory mechanisms, with men exhibiting more extensive myocardial injury and women experiencing a higher long-term symptom burden, despite overall favorable outcomes in both sexes.