Clinical significance of pleural effusions and association with outcome in patients hospitalized with a first episode of acute pericarditis

The clinical significance of pleural effusions (PLEs) in the setting of acute pericarditis remains poorly investigated. We sought to identify predictive factors for PLEs and their association with the short- and long-term prognosis of patients with acute pericarditis. We enrolled 177 patients hospitalized with a first episode of acute pericarditis. In all cases an extensive clinical, biochemical, and diagnostic work-up to detect PLEs and establish etiological diagnosis was performed. All patients included were prospectively followed for a maximum of 18 months (median 12, range 1–18) and complications were recorded. PLEs were detected in n = 94 cases (53.1% of the cohort; bilateral 53.2%, left-sided 28.7%, right-sided 18.1%) and were strongly associated with c-reactive protein (CRP) levels at admission (rho = 0.328, p