Endocarditis in children and adolescents with congenital heart defects: a Norwegian nationwide register-based cohort study.

Objectives: Congenital heart defects (CHD) are the most common birth defects worldwide and are an important cause of morbidity and early death. A significant number of deaths occur among patients with infections. CHDs predispose to the development of infective endocarditis (IE) and represent a risk factor for increased mortality due to IE. The aim of this study was to investigate the occurrence and outcomes of IE in children and adolescents with CHDs.

Methods: Data on all children with CHD and IE born in Norway between 1994 and 2016 were retrieved from the Oslo University Hospital's Clinical Registry for Congenital Heart Defects. Survivors were followed through 2016, and supplementary information was retrieved from medical records.

Results: In this nationwide register-based cohort study, which included all 1 357 543 live births in Norway between 1994 and 2016, the incidence of IE according to the European Society of Cardiology diagnostic criteria was 2.2 per 10 000 person-years among children and adolescents with CHDs. The incidence was stable throughout the period. Most patients with IE had severe CHDs (75%) and had undergone open chest cardiac surgery or catheter-based cardiac interventions the last year before IE. IE-related mortality among children with CHDs and IE was 8% during the follow-up period (mean 12.4 years (±5.5 years)).

Conclusions: The incidence of IE among children and adolescents with CHDs was higher than the reported incidence in the general population. IE was associated with severe CHDs and recent complex cardiac interventions, and had significant mortality.