Special considerations in adults with congenital heart disease: a focus on immunodeficiency and endocarditis

Background: Adults with congenital heart disease are increasingly surviving into later life owing to advances in care. Compared with the general population, they face a much higher risk of infective endocarditis, with incidence up to 44 times greater. This risk is compounded by structural heart abnormalities, prosthetic material and immunodeficiency, which is more common in subgroups such as those with DiGeorge syndrome, early thymectomy, or Fontan circulation. Together, these factors create a complex clinical profile where infection risk and diagnostic challenges are closely linked. Aim: To examine how immunodeficiency contributes to the high incidence and severity of infective endocarditis in adults with congenital heart disease, and to explore strategies for prevention, early recognition and effective management. Methods: A narrative review of current evidence, clinical guidelines and expert commentary on the relationship between immunodeficiency and infective endocarditis risk in adults with congenital heart disease. Findings: Infective endocarditis incidence in adults with congenital heart disease is markedly higher than in people without congenital heart disease, driven by structural defects, prior surgery, and increased susceptibility to infection. Immunodeficiency further raises this risk and complicates diagnosis, as symptoms are often non-specific. Preventive measures, including oral hygiene, skin care and antibiotic prophylaxis, are essential but inconsistently applied. Implications for practice: Healthcare professionals should be aware that immunodeficiency and infective endocarditis risk are closely connected in adults with congenital heart disease. Understanding individual risk factors, providing proactive education and ensuring early multidisciplinary care are critical to improving outcomes in this vulnerable population.