Background: Obesity and obstructive sleep apnea (OSA) have a strong association with atrial fibrillation (AF). The purpose of this study was to prospectively determine the effects of obesity, assessed by the body mass index (BMI) and OSA on the efficacy of catheter ablation of AF.
Methods: The patient population consisted of 109 patients (mean age: 60 +/- 10 years, 79% male, 67% paroxysmal, mean BMI 28 +/- 5 kg/m(2)) who underwent catheter ablation of AF. Based on BMI, patients were classified as normal (<25 kg/m(2)), overweight (>or=25 and <30 kg/m(2)), or obese (>or=30 kg/m(2)). OSA was assessed by the Berlin questionnaire. Clinical success was defined as at least 90% reduction in AF burden after 3-month blanking period. Mean duration of follow-up was 11 +/- 4 months.
Results: Of the 75 patients with clinical success, 25 (33%) had normal BMI, 29 (39%) were overweight, and 21 (28%) were obese. Among the 34 patients with failed outcome, 5 (15%) had normal BMI, 14 (41%) were overweight, and 15 (44%) were obese (P = 0.04). Twenty-eight of the 48 patients with OSA (58%) had clinical success as opposed to 47 of the 61 patients (77%) without OSA (P = 0.036). On multivariate analysis, only BMI emerged as an independent predictor of procedural failure ((OR 1.11, CI: 1.00-1.21, P = 0.03).
Conclusions: The results of this prospective study show that obesity, a modifiable risk factor, is an independent predictor of procedural failure after catheter ablation of AF. Whether treating obesity may improve the results of catheter ablation of AF warrants further investigation.