Atrial arrhythmias and thromboembolic complications in adults post Fontan surgery

OBJECTIVE: Patients with Fontan surgery experience late complications in adulthood. We studied the factors associated with the development and maintenance of atrial arrhythmias and thromboembolic complications in an adult population with univentricuar physiology post Fontan surgery. METHODS: Single centre retrospective cohort study of patients ≥18 years of age with Fontan circulation followed at our quaternary care centre for more than 1 year were included. Univariate and multivariate regression models were used where applicable to ascertain clinically significant associations between risk factors and complications. RESULTS: 93 patients were included (age 30.2±8.8 years, 58% men). 28 (30%) had atriopulmonary Fontan connection, 35 (37.6%) had lateral tunnel Fontan and 29 (31.1%) had extracardiac Fontan pathway. After a mean of 7.27±5.1 years, atrial arrhythmia was noted in 37 patients (39.8%), of which 13 developed had atrial fibrillation (14%). The presence of atrial arrhythmia was associated with the number of prior cardiac surgeries/procedures, increasing age and prior atriopulmonary Fontan operation. Thromboembolic events were present in 31 patients (33%); among them 14 had stroke (45%), 3 had transient ischaemic attack (9.7%), 7 had pulmonary embolism (22.6%) and 5 had atrial thrombus with imaging (16.1%). The presence of thromboembolic events was only associated with age and the presence of cirrhosis in multivariate analysis. CONCLUSIONS: Atrial arrhythmias are common in adults with Fontan circulation at an early age, and are associated with prior surgical history and increasing age. Traditional risk factors may not be associated with atrial arrhythmia or thromboembolism in this cohort.