Infective endocarditis with or without congenital heart disease: clinical features and outcomes

Background and Aims Patients with congenital heart disease (CHD) form a high-risk subgroup for infective endocarditis (IE), necessitating tailored prevention and treatment strategies. However, comprehensive nationwide data comparing IE characteristics and outcomes in patients with and without CHD, including children, are sparse. This study aims to address this gap in knowledge. Methods Using Danish nationwide registries, all patients with IE from 1977 to 2021 were identified and stratified on whether they had a diagnosis of CHD, regardless of its complexity. Characteristics prior to and during admission as well as associated outcomes (i.e. in-hospital mortality, 1-year mortality, and 10-year mortality, and IE recurrence) were compared between groups. Results In total, 14 040 patients with IE were identified, including 895 (6.4%) with CHD. Patients with vs. without CHD were younger at the time of IE diagnosis (median age 38.8 vs. 70.7 years), less comorbid, and more frequently underwent cardiac surgery during admission (35.7% vs. 23.0%, P < .001). Notably, 76% of patients with IE < 18 years of age had CHD. The IE-related bacteraemia differed between groups: Streptococci (29.9%) were the most common in patients with CHD, and Staphylococcus aureus (29.9%) in patients without CHD. Patients with CHD had a significantly lower cumulative incidence of in-hospital mortality (5.7% vs. 17.0%, P < .001) and 1-year mortality (9.9% vs. 31.8%, P < .001) compared with those without CHD. The 10-year cumulative incidence of IE recurrence was similar between groups (13.0% and 13.9%, P = .61). Conclusions Patients with CHD who develop IE exhibit distinct characteristics and improved long-term outcomes compared with patients without CHD. Notably, the majority of children and adolescents with IE have underlying CHD.