Management of the adult Fontan patient

Adults with congenital heart disease who underwent the Fontan operation to palliate single ventricle heart defects-by direct connection of caval venous return to the pulmonary circulation-have improved survival due to advancements in surgical and interventional techniques. However, cardiac and non-cardiac comorbidities often coexist, complicating management, and contributing to premature morbidity and mortality. Cardiac issues include heart failure symptoms related to systolic and diastolic dysfunction, atrial and ventricular arrhythmias and systemic atrioventricular valve regurgitation. Structural issues may be related to obstruction of the Fontan pathway, or to branch pulmonary artery stenosis, both of which exacerbate symptoms. Non-cardiac complications in adults involve hepatic congestion, fibrosis and cirrhosis, hepatocellular carcinoma, chronic kidney disease, stroke, venous stasis, lymphatic issues and involvement of other organ systems. 'Fontan failure' refers to circulatory dysfunction, either cardiac, non-cardiac, or both, diagnosed after exclusion or treatment of reversible contributors such as structural issues and arrhythmias. Counselling about reproductive health, mental health, perioperative management and overall wellness are paramount for patients' well-being. Fontan patients are typically managed in highly specialised adult congenital heart centres, but may present to cardiologists or other practitioners with cardiac and non-cardiac emergencies or urgencies, sometimes after being out of care. In this review, we discuss the management of the adult Fontan patient, including surveillance, cardiac and non-cardiac complications, reproductive health, and advanced therapies.