Long-term Outcomes of Cryoballoon-based Empirical Superior Vena Cava Isolation in Addition to Pulmonary Vein Isolation in Persistent Atrial Fibrillation.

Background: Superior vena cava (SVC) is atrial fibrillation (AF)'s most common non-pulmonary vein (PV) foci. Studies reported conflictory results when SVC isolation (SVCi) was combined with PVi and long-term outcomes were lacking. Therefore, we aimed to evaluate the long-term efficacy and safety of empirical SVCi as an adjunct to cryoballoon-based PV isolation (PVi) in persistent AF ablation.

Methods: A total of 40 consecutive persistent AF patients (60.6 ± 8.2 years, 52.5% females) who underwent SVCi in addition to PVi compared with a propensity score matched cohort of 40 persistent AF patients (58.6 ± 8.7 years, 50% female) in whom PVi-only was performed. Second-generation cryoballoon (CB2) was used in all procedures. Atrial tachyarrhythmia (ATa) recurrence was defined as the detection of AF, atrial flutter, or atrial tachycardia (≥30 s) after a 3-month blanking period.

Results: Pulmonary veins and SVC were successfully isolated in all patients. At a mean of 46.7 ± 7.8 months follow-up, 22 (55%) patients in the PVi-only group, and 27 (67.5%) patients in the PVi + SVCi group were free of ATa after the index procedure (P =.359). Phrenic nerve injury (PNI) was detected in 2 (5%) patients in the PVi-only group (during right PVi) and 2 (5%) patients in the PVi + SVCi group (during SVCi) (P = 1.00). Cox regression analysis revealed that early recurrence was the only predictor of recurrence (hazard ratio 4.88, 95% confidence interval 1.59-14.96; P =.005).

Conclusion: Long-term results of our small sample-sized study revealed that CB-based PVi + SVCi was associated with outcomes similar to the PVi-only strategy in patients with persistent AF. Although complication rates were similar between the groups, close follow-up of diaphragmatic movement is crucial to prevent PNI during SVCi.