Introduction: Comprehensive epidemiological data about the course of myocarditis and sex differ-ences are lacking.
Objectives: We aimed to investigate the current differences in the incidence, clinical characteristics, management, and outcomes of men and women with a clinical diagnosis of myocarditis in Poland in the last 10 years.
Patients and methods: The nationwide MYO‑PL (Occurrence, Trends, Management, and Outcomes of Patients with Myocarditis in Poland) database identified hospitalization records with a primary diag-nosis of myocarditis following the International Classification of Diseases and Related Health Problems, 10th Revision (ICD‑10), derived from the database of the national health care insurer; ClinicalTrials.gov identifier: NCT04827706.
Results: A total of 16 319 patients (4208 [25.8%] women and 12 111 [74.2%] men) aged over 20 years with a hospital‑based clinical diagnosis of myocarditis were included in the study. The women were older than the men (median age, 54 (36-70) and 35 (28-47) years, respectively). The incidence of myocarditis was age-, sex-, and season‑dependent. The incidence rate of myocarditis increased over time only in men. Although women were more symptomatic and demonstrated more comorbidities than men, they were less likely to be admitted to a cardiology ward or undergo diagnostic tests. Regardless of the age and sex, the patients with myocarditis had a poorer prognosis than the general population. The women aged 21-40 years had a poorer prognosis than the men of the same age.
Conclusions: The incidence of myocarditis was age-, sex-, and season‑dependent. Significant improve-ment is required in the management of myocarditis, including the initial diagnostic process, as well as short-and long‑term therapy, particularly in women.