Cryoballoon Ablation of RooF line combined with pulmonary vein Isolation for persistent atrial fibrillation (The CARFI-PerAF Randomized Clinical Trial)

Background The limited effectiveness of pulmonary vein isolation (PVI) alone using cryoballoon ablation (CBA) led to addictive ablation in procedures of persistent atrial fibrillation (AF) ablation. Roof line (RL) ablation in addition to PVI hold great promise for reduction of AF recurrence after CBA. The randomized controlled CARFI-PerAF trial aimed to prospectively investigate the efficacy of a novel CBA strategy for block of RL and reduction of AF recurrence. Methods One hundred and ten patients who were diagnosed with persistent AF were randomized into PVI group and PVI+RL group. ‘Quarter balloon ablation technique’ and ‘roof distortion technique’ were used to improve quality of RL ablation. Conduction block of RL was confirmed by both voltage mapping and upper right atrial septum pacing. Primary effectiveness was freedom from AF or atrial tachycardia absent class I/III antiarrhythmic drugs through 12-month follow-up according to ECGs collected by portable device and 24-hour Holter. Results There was no significant difference in AF recurrence between PVI group and PVI+RL group (63.5% vs 76.2%, P = 0.296) after 532.7 ± 171.0 days of follow-up. However, blocked RL was associated with a significant reduction in risk of AF recurrence in the PVI+RL group (84.0% vs 45.5%, P = 0.025). The shape of RL was the only factor affecting the success rate of RL block. Patients with ‘Regular’ shape of RL predicted a higher rate of RL block than other types (89.7% vs 56.3%, P = 0.014). Conclusions Blocked roof line ablation was associated with a significant reduction in risk of atrial fibrillation recurrence after cryoballoon ablation. Patients with ‘Regular’ shape of roof line may benefit more from roof line ablation.