Superior Vena Cava Isolation With Cryoballoon in AF Ablation: Randomized CAVAC AF Trial

Background: Superior vena cava (SVC) has been considered a specific trigger in atrial fibrillation development.

Methods: We investigated the efficacy and safety of combining cryoballoon pulmonary vein isolation (PVI) with SVC ablation compared with PVI alone in 100 patients with paroxysmal or non-long-standing persistent atrial fibrillation. Patients were randomly assigned to either the PVI+SVC ablation group or the PVI-only group. Each patient was given a mobile device to record a daily ECG and detect atrial tachyarrhythmias.

Results: The primary end point, freedom from any atrial tachyarrhythmia recurrence between 91 and 365 days post-catheter ablation, did not significantly differ between the 2 groups (62.9% versus 72%; P=0.41). However, the PVI+SVC group exhibited higher rates of phrenic nerve paralysis (20.8% versus 6%; P=0.003) and transient sinus node injury (18.8% versus 0%; P=0.001) compared with the PVI-only group. The median burden of atrial tachyarrhythmia showed no significant difference (P=0.91).

Conclusions: The addition of SVC ablation to PVI did not enhance freedom from atrial tachyarrhythmia at 12 months, and it led to increased complications. These findings do not support the routine inclusion of SVC ablation in cryoballoon procedures for first-time catheter ablation in patients with paroxysmal or non-long-standing persistent atrial fibrillation.