Introduction: 

Pulmonary vein isolation (PVI) is an established procedure to achieve rhythm control in atrial fibrillation (AF).  In obese patients, in whom AF occurs more frequently, reduced effectiveness of PVI has been observed. Therefore, this study aimed at comparing long-term efficacy of PVI between obese and non-obese patients. 

Methods: 

We enrolled 111 consecutive patients with a Body-Mass-Index (BMI) >30kg/m² (average BMI: 34.3±3.4 kg/m²; 26,1% with BMI > 35kg/m²; 8,1% > BMI 40 kg/m² undergoing PVI from our large register. Procedural data and outcomes were compared with a matched group of 115 non-obese PVI-patients (average BMI: 25.9±2.2). Long-term outcomes were analyzed. 

Results: 

Overall follow-up duration was 314 patient-years in the obese and 378 patient-years in the non-obese group. The follow-up rate was 71% in the obesity and 76% in the non-obesity group.

In both groups, AF-characteristics did not significantly differ, while known risk factors e.g. arterial hypertension, coronary artery disease, diabetes, and left atrial dilatation were significantly more prevalent in the obesity group. Procedural characteristics were almost similar in both groups and acute ablation success defined as complete PVI with sinus rhythm at the end of the ablation procedure was 98% in both groups.

During follow-up obese patients demonstrated a significant weight loss (-4.8±8.8kg) compared to non-obese (0.9±6.3kg) patients (p<0.05). In parallel, the overall recurrence rate during follow-up did not significantly differ between both groups (obesity: 39.2%, non-obesity: 43.7%). PVI related and long-term complications were comparable between groups. Obese patients did not tend to show higher stroke rates than non-obese patients. 18 pts. in the obese and 23 pts. in the non-obese group underwent a second RF PVI during follow-up. 

Conclusion:

These real-life date demonstrate that (1) obese patients may not show higher AF recurrence rates after PVI compared to patients with normal body weight when in parallel a reduction of the initial BMI occurs. (2) The reason for weight loss may be multifactorial but in part be the result of the antiarrhythmic effect of PVI. (3) Besides, PVI was found to be safe and effective in obese patients. Thus, BMI alone may not be a criterion for refusal of PVI.