Catheter Ablation for Supraventricular Tachyarrhythmias in Adults With Total Cavopulmonary Connection Fontan Palliation

BACKGROUND: Supraventricular tachyarrhythmias (ST) and atrial tachyarrhythmias (AT) are common in the Fontan population and contribute to significant morbidity and mortality. Catheter ablation of ST/AT in adults with total cavopulmonary connection (TCPC) Fontan has not been studied on a large scale using current-era technologies. OBJECTIVES: This study sought to assess outcomes of catheter ablation in adults with TCPC Fontan in the current era. METHODS: This multicenter retrospective study endorsed by the Pediatric and Congenital Electrophysiology Society and the International Society for Adult Congenital Heart Disease Research Committee was conducted in centers from North America and Europe. Acute procedural success and complications were assessed, along with freedom from recurrent atrial arrhythmias requiring intervention. RESULTS: Data was submitted for 204 ablation procedures performed on 166 patients at median age of 28 years. The predominant ventricular morphology was single left ventricle (56.7%), and 68.3% had a lateral tunnel Fontan. Tachycardia was targeted for ablation in 189 (96.9%) procedures, with intra-atrial re-entrant tachycardia accounting for 65.1% of all tachycardias. Multiple tachycardias were inducible in 55.4% of procedures. Ablation was acutely successful in 86.0% of procedures, with a complication rate of 7.9%. Probability of recurrent atrial arrhythmias requiring intervention was 31% at 1 year and 49% at 4 years. No clinical or procedural factors were found to be predictive of recurrent atrial arrhythmias. CONCLUSIONS: This report represents the largest cohort of ablation procedures in adult TCPC Fontan patients. The high acute success rate associated with catheter ablation for ST/AT is tempered by a high incidence of recurrent arrhythmias that require intervention.