Long-Term Outcome of Additional Superior Vena Cava to Septal Linear Ablation in Catheter Ablation of Atrial Fibrillation

Background: We previously reported the benefit of linear ablation from the superior vena cava to the right atrial septum (SVC-L) within a year after circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (AF). We explored the long-term effects of SVC-L and its potential related mechanisms. Methods and Results: Among 2140 consecutive patients with AF ablation, we included 614 patients (73.3% male, aged 57.8±10.7 years, 13.7% with persistent AF) who did not undergo an extra–pulmonary vein left atrial ablation after propensity score matching; of those, 307 had additional SVC-L and 307 had CPVI alone. We evaluated the heart rate variability and computational modeling study to explore mechanisms. Although the procedure time was longer in the SVC-L group than the CPVI group (P<0.001), the complication rates did not differ (P=0.560). During 40.5±24.4 months of follow-up, the rhythm outcome was significantly better in the SVC-L group than the CPVI group (log rank, P<0.001). At 2-year follow-up of heart rate variability, a significantly higher mean heart rate (P=0.018) and a lower ratio of low/high-frequency components (P=0.011) were found with SVC-L than CPVI alone. In realistic in silico biatrial modeling, which reflected the electroanatomies of 10 patients, SVC-L significantly reduced biatrial dominant frequency compared with CPVI alone (P<0.001) and increased AF termination and defragmentation rates (P=0.033). Conclusions: SVC-L ablation in addition to CPVI significantly improved the long-term rhythm outcome over 2 years after AF catheter ablation by mechanisms involving autonomic modulation and AF organization.