Abstract
BACKGROUND: The incidental finding of a pericardial effusion (PE) poses a challenge in clinical care. PE is associated with malignant conditions or severe cardiac disease but may also be observed in healthy individuals. This study explored the prevalence, determinants, course, and prognostic relevance of PE in a population-based cohort. METHODS AND RESULTS: The STAAB (Characteristics and Course of Heart Failure Stages A/B and Determinants of Progression) cohort study recruited a representative sample of the population of Würzburg, aged 30 to 79 years. Participants underwent quality-controlled transthoracic echocardiography including the dedicated evaluation of the pericardial space. Of 4965 individuals included at baseline (mean age, 55±12 years; 52% women), 134 (2.7%) exhibited an incidentally diagnosed PE (median diameter, 2.7 mm; quartiles, 2.0-4.1 mm). In multivariable logistic regression, lower body mass index and higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels were associated with PE at baseline, whereas inflammation, malignancy, and rheumatoid disease were not. Among the 3901 participants attending the follow-up examination after a median time of 34 (30-41) months, PE was found in 60 individuals (1.5%; n=18 new PE, n=42 persistent PE). Within the follow-up period, 37 participants died and 93 participants reported a newly diagnosed malignancy. The presence of PE did not predict all-cause death or the development of new malignancy. CONCLUSIONS: Incidental PE was detected in about 3% of individuals, with the vast majority measuring <10 mm and completely resolving. PE was not associated with inflammation markers, death, incident heart failure, or malignancy. Our findings corroborate the view of current guidelines that a small PE in asymptomatic individuals can be considered an innocent phenomenon and does not require extensive short-term monitoring.