Background: Infective endocarditis (IE) in pediatric patients is a severe cardiac disease and its actual epidemiology and clinical outcome in Switzerland is scarcely studied.

Methods: Retrospective nationwide multicenter data analysis of pediatric IE in children (<18 years) between 2011 and 2020.

Results: 69 patients were treated for definite (40/69;58%) or possible IE (29/69;42%). 61% (42/69) were male. Diagnosis was made at median 6.4 years (IQR 0.8-12.6) of age with 19 patients (28%) during the first year of life. 84% (58/69) had congenital heart defects. IE was located on pulmonary (25/69;35%), mitral (10/69;14%), tricuspid (8/69;12%) and aortic valve (6/69;9%), and rarely on ventricular septal defect (VSD;4/69;6%) and atrial septal defect (ASD;1/69;1%). In 22% (16/69) localization was unknown. 70% (48/69) had postoperative IE, with prosthetic material involved in 60% (29/48; right ventricular to pulmonary artery conduit (24), VSD (4), ASD (1)). Causative organisms were mostly Staphylococci spp. (25;36%) including Staphylococcus aureus (19;28%), and Streptococci spp. (13;19%). 51% (35/69) suffered from severe complications including congestive heart failure (16;23%), sepsis (17;25%) and embolism (19;28%). Staphylococcus aureus was found as a predictor of severe complications in univariate and multivariate analysis (p = 0.02 and p = 0.033). In 46% (32/69) cardiac surgery was performed. 7% (5/69) died.

Conclusions: IE in childhood remains a severe cardiac disease with relevant mortality. The high morbidity and high rate of complications is associated with Staphylococcus aureus infections. Congenital heart defects act as a risk factor for IE, in particular the high number of cases associated with prosthetic pulmonary valve needs further evaluation and therapeutic alternatives.