Body Fat Distribution and Left Atrial Reverse Remodeling After Catheter Ablation for Atrial Fibrillation

Background Emerging evidence suggests a pathophysiological link between obesity and atrial fibrillation (AF). However, the contribution of body fat distribution to left atrial (LA) remodeling and its reversibility remain unclear in nonobese AF patients. Objectives The purpose of this study was to investigate the association of body fat distribution with LA size and reverse remodeling (LARR). Methods In total, 116 nonobese patients with AF (88 men, age 63 ± 11 years) who underwent first catheter ablation (CA) were included. Body fat distribution was assessed with bioelectrical impedance, and body fat percentage (BF%) and central fat percentage (CF%) were calculated. Patients were categorized by body size metrics (body mass index [BMI] and waist-to-hip [W/H] ratio) and fat parameters (BF% and CF%). Echocardiography was performed before and 6 months after CA. Multivariable logistic regression was used to examine the association between the 4 metrics (ie, BMI, W/H ratio, BF%, and CF%) and a lack of LARR (<15% reduction or increase in the LA volume index). Results Body size metrics and adiposity measures were not independently associated with baseline LA size. Six months after CA, the higher W/H ratio and CF% groups exhibited persistent LA enlargement compared to their counterparts (both P < 0.01). In the multivariable analysis, W/H ratio and CF% were associated with a lack of LARR (adjusted ORs of 3.86 and 2.81 per 0.10 and 10% increase, respectively, both P < 0.01). The combined assessment of CF% with W/H ratio provided complementary risk stratification for persistent LA enlargement. Conclusions Central adiposity was associated with a lack of LARR after CA, highlighting the importance of assessing body fat distribution even in nonobese patients.