Poller, Wolfgang

Abstract Background The risk of adverse cardiovascular events in patients with acute myocarditis (AM) and desmosomal gene variants (DGV) remains unknown. Purpose To ascertain the risk of death, ventricular arrhythmias, recurrent myocarditis, and heart failure (main endpoint) in patients with AM and pathogenic or likely pathogenetic DGV. Methods In a retrospective international study from 23 hospitals, 97 patients were included: 36 with AM and DGV (DGV(+)), 25 with AM and negative gene testing (DGV(−)), and 36 AM patients without genetics (w/o genetics). All patients had troponin elevation plus findings consistent with AM on histology or at cardiac magnetic resonance imaging (CMRI). In 86 patients CMRI changes in function and structure were re-assessed at follow-up. Results In the DGV(+) AM group (88.9% DSP variants), median age was 24 years, 91.7% presented with chest pain, and median left ventricular (LV) ejection fraction was 56% on CMRI (p=NS vs. the other 2 groups). Kaplan-Meier curves demonstrated a higher risk of the main endpoint in DGV(+) AM compared to DGV(−) and w/o genetics patients (62.3% vs. 17.5% vs. 5.3% at 5 years respectively; p<0.0001), driven by myocarditis recurrence and ventricular arrhythmias (Figure 1A, B). At follow-up CMRI, a higher number of late-gadolinium enhanced segments was found in DGV(+) AM. Conclusions Patients with AM and evidence of DGV have a higher incidence of adverse cardiovascular events compared with AM patients without DGV. Further prospective studies are needed to ascertain if genetic testing might improve risk stratification of patients with AM who are considered at low risk. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health

Introduction: Studying the clinical nature of myocarditis on a broad scale across age and sex groups is required to investigate risk factors and patterns of disease. This study aimed to examine patient- and hospital-centered characteristics of patients being hospitalized for myocarditis. Hypothesis: Sex differences in myocarditis prevalence are dependent on age. Methods and Results: We included all patients being hospitalized in three tertiary care centers between 1999 and 2021 with a diagnosis of acute or chronic myocarditis. We utilized Chi-square, T-test, Fisher exact or Wilcoxon-Mann-Whitney U tests. 7,031 patients with acute or chronic myocarditis were included in total. 231 (3.3%) were of pre-pubescent age (<13 years if male, <11 years if female), 410 (5.8%) were adolescent patients (<18 years), 2,089 (29.7%) young adults (18-35 years), 2,535 (36.1%) middle-aged adults (35-54 years) and 1,766 (25.1%) patients were over 54 years (post-menopausal age). The diagnosis of myocarditis was confirmed by endomyocardial biopsy in 1,337 patients (19%), while it was based on clinical parameters and/or magnetic resonance imaging in the remaining patients. Adolescent patients had the highest levels of procalcitonin (6.98 ±44.6 μg/l), troponin T (450 ±1,550 ng/l) and creatine kinase (360 ±677U/l), while pre-pubescent patients had the highest levels of anti-streptolysin antibody (320 ±470 kU/l) and NT-proBNP (14,000 ±20,800ng/l) compared to all other age groups. Left-ventricular ejection fraction decreased over age groups from 60 ±4% in adolescent patients to 44.0 ±16% in senior patients. The strongest sex difference in myocarditis frequency was observed in young (608 female vs. 1,481 male; P<0.001) and middle-aged adults (1,025 female vs. 1,510 male; P<0.001) (see Figure 1). Conclusion: Strong sex differences in myocarditis prevalence were particularly observed in young and middle-aged patients. Sex hormones may determine the risk of developing myocarditis.