Sex Based Differences in Clinical Characteristics of Patients with Acute Myocarditis: A Cohort Study

Background This study investigated sex differences in acute myocarditis patients during index hospitalization. Methods We included 365 patients with acute myocarditis, hospitalized with continuous monitoring at the Intensive care unit (ICU), from 2000-2023 into the Basel Myocarditis Cohort study. We compared sex differences in clinical presentation, the presenting ECG prior medical history, inflammatory and cardiac biomarkers, cardiac imaging, arrhythmia occurrence and short to midterm outcomes. Results Mean age was 41.3 years and 26.3% were female. Compared to men, women were older (median 49.7 vs 38.3 years, p<0.001) at the time of diagnosis and presented more frequently with dyspnea (41 vs 26%, p=0.013) and a higher Killip class (p=0.011). In the presenting ECG, men had a higher occurrence of diffuse ST-elevation (38 vs 9%, p<0.001) and PQ-depression (31 vs 20%, p=0.042), compared to women. Women had higher NT-proBNP levels (1180 vs 387 ng/l, p=0.015), lower cardiac troponin T levels (389 vs 726 ng/l, p=0.006), less segments with non-ischemic LGE on CMR (1 vs 3, p=0.005) but similar LVEF (55 vs 55%, p=0.629), compared to men. Overall, hospital stay was longer in women compared to men (7 vs 5 days, p=0.018) with a similar length of ICU stay (2.6 vs 2.7 days, p=0.922). Women developed more often severe arrhythmia (8.3 vs 2.2%, p=0.015) and heart failure during the hospitalization (31.3 vs 16.4%, p=0.003). Conclusion Compared to men, women with acute myocarditis were older at the time of diagnosis, presented more often with heart failure and had an increased frequency of severe arrhythmia.