Sex-related differences in clinical presentation and outcomes of a first episode of acute myocarditis

Introduction

Sex differences are recognized across cardiovascular diseases, but contemporary data on acute myocarditis (AM) remain limited. Women are often underrepresented and may present atypically, resulting in diagnostic delays and uncertain outcomes. We aimed to investigate sex-specific differences in patients presenting with AM.

Methods

Retrospective, observational study of consecutive patients diagnosed with a first episode of AM at a single tertiary center between January 2010 to March 2023. Diagnosis was established according to ESC criteria and isolated pericarditis was excluded. Data on demographics, comorbidities, management, and outcomes were collected. Patients were followed until August 2024.

Results

A total of 161 patients were included, 120 (74.5%) were male and 41 (25.5%) were female. Women were older (median 40 vs 33 years, p=0.009) and had higher rates of hypertension, anemia, obesity, valvular heart disease, renal disease, and immunocompromised status. Men more frequently presented with ST-segment elevation (51% vs 32%, p=0.045) and higher peak troponin (0.69 vs 0.28 ng/mL, p=0.03), whereas women had higher NT-proBNP (1024 vs 340 pg/mL, p=0.024), PCR (114 vs 56 mg/L, p=0.048), and heart failure at presentation (17% vs 5%, p=0.022). Women also showed more pericardial involvement (pericarditis 76% vs 51%, p=0.006; effusion 42% vs 13%, p<0.01). Women more frequently had left ventricular dysfunction (43.9% vs 20.8%, p=0.007) but were less likely to undergo cardiac magnetic resonance (56.1% vs 77.5%, p=0.015). No significant differences were observed in presumed etiology, biopsy rates and specific treatment.

Women had more in-hospital complications, including atrial fibrillation (15% vs. 2%, p=0.004) and cardiogenic shock (17% vs. 3%, p=0.003), and all in-hospital deaths occurred in women [3(7%)]. During a median follow-up of 15 months, long-term outcomes were similar, with no significant differences in mortality (16.2% vs. 6.6%, logrank p=0.394) or recurrent myocarditis (5.9% vs. 2.9%, p=0.596).

Conclusion

Despite male predominance and lower peak troponin, women exhibited a higher comorbidity burden, greater myocardial dysfunction, and a higher rate of in-hospital complications, which may reflect the impact of age, comorbidities, or potential underdiagnosis in women with subtle symptoms. Although interpretation of long-term outcomes is limited by the low number of events, outcomes appeared similar, and further studies are needed.For image description, please refer to the figure legend and surrounding text.