Background—: The clinical profile with regard to sex and the influences on outcomes in patients who have been hospitalized for acute pericarditis is largely uncharacterized. Methods and Results—: We studied all patients aged ≥16 years admitted to the hospital because of acute pericarditis (postpericardiotomy and myocardial infarction associated pericarditis were excluded). Data were collected from a Finnish national registry that included data on all cardiovascular admissions (670 409) during 9.5 years in 29 hospitals nationwide. During the study period, there were 1361 admissions for acute pericarditis. Pericarditis patients were more likely to be male (64.9% of patients) than female (35.1%), with an age-adjusted likelihood ratio of 1.85 (95% confidence interval [CI], 1.65–2.06; P <0.0001) for male sex. The standardized incidence rate of hospitalizations for acute pericarditis was 3.32 per 100 000 person-years. Men 16 to 65 years of age were at higher risk for pericarditis (relative risk, 2.02; 95% CI, 1.81–2.26; P <0.0001) than women in the general admitted population, with the highest risk difference among young adults. Acute pericarditis caused 0.20% (95% CI, 0.19%–0.22%) of all cardiovascular admissions. The proportion of pericarditis-caused admissions declined by an estimated 51% per 10-year increase in age. The in-hospital mortality rate for acute pericarditis was 1.1% (95% CI, 0.6%–1.8%). Mortality increased with age (hazard ratio, 3.26; 95% CI, 1.78–5.95 per 10-year increase in age; P =0.0001) and severe coinfection (pneumonia or septicemia; hazard ratio, 13.46; 95% CI, 2.26–80.01; P <0.005) but was not associated with sex in multivariate analysis. Conclusions—: Patients hospitalized for acute pericarditis are more commonly male. Increasing age and severe coinfection are associated with greater in-hospital mortality in hospitalized acute pericarditis patients.

Objective To study the effects of gender and age on occurrence of myocarditis. Design Nationwide, multicentre registry study in Finland. Setting All medical hospital admissions (n=1 698 397) of patients aged ≥16 years during 9.5 years in 29 hospitals. Patients 3198 myocarditis patients. Results Myocarditis was more common in men (76.61%; 95% CI 75.11% to 78.05%) than in women (23.39%; 95% CI 21.95% to 24.89%, p<0.0001). Median age of patients was 33 years (IQR 23–50 years). Male patients were significantly younger than females (mean age 34.1±SD 15.1 vs 49.0±18.7 years, p<0.0001). In men, occurrence was highest at 16–20 yrs of age, with a linear decline to elderliness (r=−0.95, p<0.0001). By contrast, myocarditis affected women more evenly at all ages with highest occurrence at the age of 56–60 years. Myocarditis caused 0.19% (95% CI 0.18% to 0.19%) of all medical admissions, and 0.48% (95% CI 0.46% to 0.49%) of admissions due to cardiovascular reasons with an inverse logarithmic association with age (r=−0.97, p<0.0001). Admissions were more commonly caused by myocarditis in men (risk ratio 3.11; 95% CI 2.87 to 3.38, p<0.0001). Conclusions Men are significantly more susceptible to myocarditis than women. Young men are especially at risk for acquiring myocarditis, while women are affected most commonly at the postmenopausal age. The proportion of hospital admissions caused by myocarditis has an inverse, logarithmic association with age.

Background: Epidemiology of myocarditis in childhood is largely unknown. Men are known to have a higher incidence of myocarditis than women in adults aged <50 years, but whether this is true by sex in pediatric age groups is unknown. We set out to study the occurrence and potential sex differences of myocarditis in a general pediatric population. Methods and Results: Data of all hospital admissions with myocarditis in Finland occurring in patients aged ≤15 years from 2004 to 2014 were collected from a mandatory nationwide registry. All patients with myocarditis as a primary, secondary, or tertiary cause of admission were included. Total and age‐ and sex ‐ specific incidence rates were calculated using corresponding population data. There were 213 admissions with myocarditis in pediatric patients. Myocarditis was the primary cause of admission in 86%. The overall incidence rate of myocarditis was 1.95/100 000 person‐years. Of all patients, 77% were boys, but sex differences in incidence rates were age‐dependent. In children aged 0 to 5 years, there was no sex difference in the occurrence of myocarditis. Boys aged 6 to 10 years had a higher incidence rate compared with girls (72% boys; incidence rate ratio: 2.46; 95% confidence interval, 1.03–5.89; P =0.04). Sex difference further increased in children aged 11 to 15 years (80% boys; incidence rate ratio: 3.5; 95% confidence interval, 2.68–5.67; P <0.0001). Conclusions: Myocarditis leading to hospital admission is relatively uncommon in children, but occurrence of myocarditis increases with age. There is no sex difference in the risk of myocarditis during the first 6 years of life, but boys have a significantly higher risk at ages 6 to 15 years.

Cases of PML should be evaluated according to predisposing factors, as these subgroups differ by incidence rate, clinical course, and prognosis. The three most significant groups at risk of PML are patients with hematological malignancies mostly previously treated with immunotherapies but also untreated, patients with HIV infection, and patients using monoclonal antibody (mAb) treatments. Epidemiological data is scarce and partly conflicting, but the distribution of the subgroups appears to have changed. While there is no specific anti-JCPyV treatment, restoration of the immune function is the most effective approach to PML treatment. Research is warranted to determine whether immune checkpoint inhibitors could benefit certain PML subgroups. There are no systematic national or international records of PML diagnoses or a risk stratification algorithm, except for MS patients receiving natalizumab (NTZ). These are needed to improve PML risk assessment and to tailor better prevention strategies.