Background:
Management of atrial fibrillation (AF) in extremely obese patients can be challenging. As a rhythm control strategy, cryoballoon (CB) ablation represents an effective modality to treat AF. However, the feasibility, procedural data and clinical results of CB ablation in patients with obesity class III and symptomatic atrial fibrillation (AF) were seldomly reported.

Methods:
Highly symptomatic AF patients with BMI≥40 kg/m2, who underwent CB ablation, were consecutively enrolled. Patient baseline characteristics, CB ablation procedural data and follow-up data were analyzed.

Results:
72 patients were included (40% male; 60,6 ± 10,4 years old). Procedural successful pulmonary vein isolation (PVI) was achieved in 100% of patients. Of the 284 targeted PVs, 280 (98,6%) were isolated using solely the CB, and 4 PVs in 2 patients needed touch-up radiofrequency (RF) ablation. Procedural and fluoroscopy times were 61,3 ± 22,6 and 10,1 ± 5,5 respectively, and radiation dose was 2851,6 ± 2095 uGym2. Procedural complications rate was 12,5% (9/72) and the complications at access site, specifically pseudoaneurysm or arteriovenous fistula, represent the majority of the complications (5/9; 55,6%). The single procedure clinical freedom from AF/atrial tachycardia (ATa) at 1-year was 68,9%.

Conclusion:
Cryoballoon based PVI in severely obese patients is feasible and can be achieved without serious complications and with relatively good clinical outcome. The most frequent procedural adverse event is groin puncture site complication.