The impact of body mass index on the efficacy and safety of catheter ablation of atrial fibrillation.

Background: Obesity is a well established risk factor for atrial fibrillation (AF) development. Our purpose was to determine the impact of body mass index (BMI) on the safety and efficacy of radiofrequency catheter ablation of AF.

Methods: Two hundred and twenty-six consecutive patients with symptomatic, drug-refractory paroxysmal (59.3%) and persistent (40.7%) AF underwent wide circumferential electrical pulmonary vein isolation. Patients were classified according to BMI as normal (<25kg/m(2)); overweight (25 to 29.9kg/m(2)); and obese (≥30kg/m(2)).

Results: Patients with high BMI were younger and displayed a higher rate of hypertension, increased left atrial diameter, increased left ventricular end-diastolic and end-systolic diameters, and increased levels of several conventional markers of inflammation and oxidative stress including white blood cell count, fibrinogen, uric acid, alanine aminotransferase, and gamma-glutamyltransferase (p<0.05). After a mean follow-up period of 432.32±306.09days from the index procedure, AF recurrence rate was 34.9% for normal weight, 46.2% for overweight, and 46.2% for obese patients (p: 0.258). Subjects classified above the 50th percentile for BMI displayed a trend toward a higher AF recurrence rate (p: 0.08). In univariate Cox regression survival analysis, BMI was not predictive of AF recurrence. Radiation exposure was significantly higher in overweight and obese patients in relation to normal weight patients (p: 0.003). No significant differences regarding major complications were observed among BMI groups.

Conclusions: In this study population, BMI was not an independent predictor of AF recurrence following left atrial catheter ablation.