Long-Term Outcomes and Predictors of Recurrence in Atrial Arrhythmia Ablations Post-Fontan Procedure: A Retrospective Analysis.

Background: Supraventricular tachycardia (SVT) is common in patients who have undergone a Fontan procedure and is poorly tolerated. SVT recurrence rates after catheter ablations are high. Recent data on the outcomes of SVT ablation and the predictors of recurrence in this population are limited.

Methods: Electronic medical records of patients who had undergone a Fontan procedure and SVT ablation between January 1, 1995, and October 1, 2023, at a tertiary care center were reviewed. Demographic, clinical, and outcome variables over 5 years were compared between patients with and without SVT recurrence.

Results: Twenty-five patients (56% male, mean age 31.5 ± 7.2 years) with a mean age of 6.1 ± 3.6 years at Fontan surgery were included. Ablation success rate was 92%. Recurrence occurred in 12 (48%) patients, of whom 7 (28%) required repeat ablations. Thirteen (59%) patients had a cardiac hospitalization, and one patient died in the 5-year follow-up period. Atypical (71%) and typical (33%) right atrial flutter were the most common SVTs. Higher brain natriuretic peptide (BNP) levels pre- (1,702 vs. 242, P = 0.028) and post-ablation (862 vs. 112, P = 0.017) were associated with recurrence. Atriopulmonary (AP) Fontan type (91% vs. 17%, P = 0.0006), number of radiofrequency (RF) applications (48 vs. 14, P = 0.045), post-ablation cardiovascular (CV) hospitalizations (82% vs. 36% P = 0.030), and post-ablation antiarrhythmic prescriptions (1.8 vs. 1.2, P = 0.0256) were more prevalent in patients with recurrence.

Conclusion: Catheter ablation of SVT in patients with Fontan physiology is associated with a high success rate and a high long-term recurrence rate. Recurrence of SVT is associated with markers of severe heart disease and type of Fontan.