Body mass index, obstructive sleep apnea, and outcomes of catheter ablation of atrial fibrillation

Background: Obesity and obstructive sleep apnea (OSA) are associated with atrial fibrillation (AF). The effects of a large body mass index (BMI) and OSA on the results of radiofrequency catheter ablation (RFA) of AF are unclear. Objective: To evaluate the effect of BMI and OSA on the efficacy of RFA for AF. Methods: RFA was performed in 324 consecutive patients (mean age = 57 +/- 11 years) with paroxysmal (234) or chronic (90) AF. OSA was diagnosed by polysomnography in 32 of 324 patients (10%) prior to ablation. Among the 324 patients, 18% had a normal BMI (<25 kg/m(2)), 39 % were overweight (BMI >= 25 kg/m(2) and <30 kg/m(2)), and 43% were obese (>= 30 k g/m(2)). RFA was performed to eliminate complex fractionated atrial electrograms (CFAE) in the pulmonary vein antrum and left atrium. Results: At 7 +/- 4 months after a single ablation procedure, 63 % of patients without OSA and 41 % with OSA were free from recurrent AF without antiarrhythmic drug therapy (P = 0.02). Multivariate analysis including variables of age, gender, type and duration of AF, OSA, BMI, left atrial size, ejection fraction, and hypertension demonstrated that OSA was the strongest predictor of recurrent AF (OR = 3.04, 95% CI: 1.11-8.32, P = 0.03). There was no association between BMI and freedom from recurrent AF. A serious complication occurred in 3 of 324 patients, with no relationship to BMI. Conclusions: OSA is a predictor of recurrent AF after RFA independent of its association with BMI and left atrial size. Obesity does not appear to affect outcomes after radiofrequency catheter ablation of AF.