Impact of body mass index on cryoablation of atrial fibrillation: Patient characteristics, procedural data, and long-term outcomes

Introduction Ablation of atrial fibrillation in the context of obesity can be challenging. We sought to evaluate the role of cryoballoon pulmonary vein isolation (CB-PVI) in obese patients with symptomatic atrial fibrillation (AF). Methods Patients with a BMI >= 25 kg/m(2) and symptomatic AF who underwent CB-PVI were retrospectively enrolled. Three groups were defined (G1: BMI of 25-29 kg/m(2); G2: BMI of 30-34 kg/m(2); G3: BMI >= 35 kg/m(2)). Results 600 patients were included (59% male; 66 +/- 11 years old); 337, 149, and 114 were assigned to G1, G2, and G3, respectively. Acute procedural success was recorded in 99.7% of patients. Procedural and fluoroscopy time were comparable but the radiation dose was significantly higher in G3. Procedural complications were 3% in G1, 5.4% in G2, and 8.8% in G3 (p = .01). The overall freedom from AF after 1-year was 77%. G3 had a significantly worse 1-year success rate compared to G1 and G2 (G3: 66.5% vs. G1: 78.4%; p = .015 and vs. G2: 82.5%; p = .008) with reduced 1-year success in paroxysmal AF (G1: 84.0%; G2: 86.3%; and G3: 69.6%) but not in persistent AF (G1: 68.7%; G2: 77.4%; and G3: 62.1%). G3 showed similar success rates irrespective of AF form (PAF: 69.6% vs. persAF 62.1%; p = .501). Conclusion Cryoballoon ablation in obese patients can be effective with an acceptable safety profile, 77% of patients were in stable SR at 1 year. Severe obese patients (BMI >= 35) showed reduced procedural safety and 1-year success rate. In association with life style modification, CB ablation may represent a strategy to enhance rhythm control in the context of obesity.