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

This study investigated sex differences in acute myocarditis patients during index hospitalization. We included 365 patients with acute myocarditis, hospitalized with continuous monitoring at the intensive care unit from 2000-2023 into the Basel Myocarditis Cohort study. We compared sex differences in clinical presentation, the presenting electrocardiogram, prior medical history, inflammatory and cardiac biomarkers, cardiac imaging, arrhythmia occurrence, and short- to midterm outcomes. Mean age was 41.3 years, and 26.3% were female. Compared with men, women were older (median 49.7 vs 38.3 years, P < .001) at the time of diagnosis and presented more frequently with dyspnea (41 vs 26%, P = .013) and a higher Killip class (P = .011). In the presenting electrocardiogram, men had a higher occurrence of diffuse ST-elevation (38 vs 9%, P < .001) and PQ-depression (31 vs 20%, P = .042), compared with women. Women had higher N-terminal pro B-type natriuretic peptide levels (1180 vs 387 ng/L, P = .015), lower cardiac troponin T levels (389 vs 726 ng/L, P = .006), and fewer segments with nonischemic late gadolinium enhancement on cardiac magnetic resonance imaging (1 vs 3, P = .005), but similar left ventricular ejection fraction (55 vs 55%, P = .629), compared with men. Overall, hospital stay was longer in women compared with men (7 vs 5 days, P = .018), with a similar length of intensive care unit stay (2.6 vs 2.7 days, P = .922). Women more often developed severe arrhythmia (8.3 vs 2.2%, P = .015) and heart failure during the hospitalization (31.3 vs 16.4%, P = .003). Compared with 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.