High-power, short-duration ablation during Box isolation for atrial fibrillation

It has been demonstrated that a high-power, short-duration (HPSD) ablation during pulmonary vein (PV) isolation is effective and safe. However, studies about the HPSD ablation during the posterior wall isolation, the Box isolation (BOXI), are limited. We evaluated the efficacy, feasibility, and safety of HPSD ablation during BOXI.

One-hundred sixty patients with all types of atrial fibrillation underwent BOXI with HPSD ablation (n = 80) or conventional technique (n = 80). In the HPSD group, ablation was performed with 50 W and a target lesion size index of 5.0 using a contact force (CF) sensing catheter. Ablation near the esophagus was performed with 50 W for 5 seconds and a CF < 10 g. In the conventional group, ablation was performed with 30-40 W for 30 seconds, but 20 W near the esophagus.

The BOXI creation (26 ± 8 minutes vs 47 ± 17 minutes, P < .0001) and procedure (65 ± 12 minutes vs 87 ± 23 minutes, P < .0001) times were significantly shorter in the HPSD group than the conventional group. The number of pacing capture sites did not differ between the two groups. No complications including gastrointestinal symptoms occurred. The atrial tachyarrhythmia-free rate at 12-months after a single procedure was 86.3% in the HPSD group and 76.3% in the conventional group, respectively (P = .132). The incidence of PV reconnections and gaps in the lines during the second procedure did not differ between the two groups.

The BOXI with HPSD ablation is effective, feasible, and safe with short BOXI creation and procedure times without reducing the clinical outcomes.