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.