Abstract 2875: Impact of Obesity on Characteristics of Atrial Fibrillation and Outcomes of Ablation
Background: Obesity is associated with an increased occurrence of atrial fibrillation (AF). The outcome of catheter ablation for AF in this specific population is unknown. We hypothesized that obesity alters the atrial substrate and thereby decreases efficacy of AF ablation.
Methods: This study cohort consisted of 259 patients (pts, male 223, mean age 56±10 ys) who underwent wide area circumferential ablation (WACA) for drug refractory AF at Mayo Clinic from 11/2000 to 10/2004. The primary endpoint was freedom from AF (AF elimination) with a secondary endpoint of AF control on antiarrhythmic drugs (AADs). Patients were divided into body mass index (BMI) ≤25 (normal weight), 25–30 (over weight), and >30 (obese) groups.
Results: Eighty four percent (218/259) of pts who underwent WACA were overweight including 43% (112/259) of them in the obese group. The comparisons of baseline clinical demographics and outcome after AF ablation among 3 groups were as shown in the table⇓ (*: p<0.05 compared to BMI <25). Persistent/permanent AF and hypertension were more often present in pts with increased BMI in this ablation cohort. There were no significant differences in AF duration, the number of failed AADs, left ventricular function, and left atrial enlargement among the three groups. The AF elimination rate was lower in obese pts compared to those with normal weight (see table⇓). AADs in conjunction with AF ablation improved and equalized the efficacy of AF ablation.
Conclusion: Symptomatic persistent/permanent AF and hypertension are more frequently encountered in obese pts and had a negative impact on the efficacy of AF ablation. Continued AAD is frequently required in obesity to achieve AF control.