Introduction: Obesity is related with a higher incidence of atrial fibrillation (AF). Comparison of obesity and atrial epicardial adipose tissue (AEAT) and to higher levels of visceral adipose tissue is also documented. AEAT with its paracrine effects, is linked to a more extensive remodeling of LA. Mediastinal adipose tissue (MAT) is not extensively researched regarding AF. Pulmonary Vein Isolation (PVI) is the recommended procedure during AF catheter ablations procedures. However, in nearly half of patients with persistent AF, significant low voltage areas (LVAs) could be documented during electrophysiological study (EP). The remaining presence of these areas after PVI only is associated with a high recurrency of AF. However, a direct link of the role of obesity in form of body mass index (BMI), MAT or AEAT with the presence of LVAs is to our knowledge not yet fully evaluated. Identifying these parameters as preprocedural markers of LVAs is intriguing. Aim of the study: is to evaluate role of BMI, AEAT and MAT in the presence of low voltage areas in LA besides PV by comparing these parameters in patients with persistent AF, with and without LVAs in LA and eventually to identify these parameters as possible pre-procedural markers of the presence of these areas. Methodology: We analyzed 100 consecutive patients with persistent AF undergoing first time LA catheter ablation. In all patients a high-density 3D endocardial voltage mapping and a ECG-synchronized Computed Tomography (CT) of LA was performed. Results: 26 patients (26%) were females, average age was 66,5±8.3 years. Average LV-EF was 53.3±10.9%. Average BMI was 29.8±5.1 kg/m2. Average Volume of AEAT in respect to LA Volume Index (vAEAT/LAVI) was 0.9±0.5ml/ml/m2, average density of AEAT (dAEAT) was -59.9±7.9 Hounsfield units (HU), average volume of MAT in respect to BMI (vMAT/BSA) was 147.7±67.4HU/m2, average density of MAT (dMAT) was -80.4±9.5 HU. Significant LVAs were detected in 18 Patients (18%). A significant positive correlation of BMI with vAEAT (r=0.491; p<0.001) and vMAT (r=0.504; p<0.001) was observed. A significant negative correlation between vAEAT and dAEAT (r=-0.396; p<0.001) and also between vMAT and dMAT (r=-0.551; p<0.001) was observed. Between Patients with and without LVAs there was no significant statistical difference in BMI (29.4±5.1kg/m2 vs 30 ± 5.1kg/m2; p=0.684), vAEAT/LAVI (0.8±0.3ml/ml/m2 vs 0.9±0.5ml/ml/m2; p=0.26), dAEAT(-61.1±6.3HU vs -59.7±8.2HU; p=0.534), vMAT/BSA (147.4±79.9HU/m2 vs 152.2±66.9HU/m2; p=0.801) and dMAT (-78.4±9.2HU vs 80.6±9.8HU; p=0.39). No gender differences were observed. Discussion and conclusion: Even though obesity is related to a higher incidence and burden of AF, its related parameters such as BMI, MAT as representative of visceral fat and AEAT with its paracrine effects in LA, were not related with a higher incidence of LVA. Therefore a rather diffuse than localized remodeling of LA has taken place, resulting in a higher incidence and recurrence of AF. vAEAT, dAEAT, vMAT in addition to BMI are not relevant pre-procedural markers for the presence of LVA.
