Risk Factors for Morbidity and Mortality Following Hospitalization for Pericarditis

Viral or idiopathic pericarditis is a frequent condition, often considered benign, although prior studies have suggested that pericarditis is associated with both cardiovascular and noncardiovascular disease, for example, malignancy. This study sought to assess mortality risk and morbidity patterns in patients with incident viral or idiopathic pericarditis. In nationwide Danish registries, we identified patients discharged with a first-time diagnosis of pericarditis from 1996 to 2016. Patients with a severe underlying heart condition were excluded. The patients were matched 1:10 with individuals from the general population by sex and year of birth. We assessed 5-year mortality using Kaplan-Meier and Cox proportional hazards models adjusted for baseline comorbidities and identified subsequent hospital admissions. We identified 7,988 patients with pericarditis and 79,880 matched control individuals. The absolute 5-year survival probability was 92.9% and 95.8% in the pericarditis and control groups, respectively (adjusted hazard ratio: 1.31; 95% confidence interval: 1.13 to 1.52). The greatest difference in mortality was seen the first year, and it was primarily driven by the female part of the population. The incidence rate per 1,000 person-years of new-onset, admission-required diagnosis was higher in the pericarditis group both for cardiovascular and noncardiovascular diseases. We observed a higher mortality risk over 5 years in the pericarditis group, especially among the female patients, compared to matched control individuals. Furthermore, we observed a higher frequency of both cardiovascular and noncardiovascular hospital admissions, highlighting the need for focus on underlying morbidity in patients presenting with apparent viral or idiopathic pericarditis. [Display omitted]