Impact of Body Mass Index on the Outcomes of Cryoballoon Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation.

Background: Atrial fibrillation (AF) is prevalent among obese patients, and cryoballoon ablation (CBA) is an effective strategy for the rhythm control of AF. The impact of body mass index (BMI) on the clinical outcomes of CBA for AF is not fully explored.

Methods: 85 consecutive patients with paroxysmal AF were enrolled and were categorized into three groups as per their BMI: normal weight (BMI 18.5-25 kg/m²), overweight (BMI 25-30 kg/m²), and obese patients (BMI > 30 kg/m²). The primary study endpoint was a late (12 month) recurrence of AF. Early recurrence of AF, symptom improvement, and procedural outcomes were some key secondary outcomes.

Results: 20 patients had normal weight, 35 were overweight, and 30 were obese. Obese patients featured a higher prevalence of diabetes mellitus, heavier exposure to smoking, and worse baseline symptoms (as assessed through EHRA class at admission and 12 months before CBA) compared to overweight and normal weight patients. Both late and early (<3 months) AF recurrence rates were comparable across the three groups. Of note, obese patients showed greater improvement in their symptoms post-CBA, defined as improvement by at least one EHRA class, compared to normal weight patients; this might be explained by improved diastolic function. Total procedure time and dose area product were significantly increased in obese patients. The multivariate logistic regression analysis indicated that early AF recurrence and the duration of hypertension are independent predictors of late AF recurrence.

Conclusion: CBA is effective in overweight and obese patients with paroxysmal AF. Procedure time and radiation exposure are increased in obese patients undergoing CBA.