Epicardial atrial fat and left atrium remodeling

Background Increasing data have reported a potent link between epicardial atrial fat (EAF) and atrial fibrillation (AF) that could contribute to atrial substrate remodeling through its paracrine function. High burden of AF is associated with progressive left atrium (LA) structural remodeling but little is known about the relationship between LA reverse remodeling (LARR) and EAF thickness evolution according to AF burden. The objective of the study was to evaluate EAF thickness using 2 consecutive CT scan in a cohort of patients with recurrent AF after ablation and to analyze its relation with LA volume and LARR. Methods We included 90 patientswho had a first AF ablation and a redo procedure along with two computed tomographies (CT). EAF thickness and LARR defined as a 15% reduction of LA volume were measured on 2 consecutive CT. The patients were divided into two groups–those with LARR (LARR +) and those without (LARR-). Results LARR occurred in 23% (21) of the cohort despite AF recurrence in both group. There was no significant difference in terms of age, BMI, cardiovascular risk factors between the two groups. LA volume was the only multivariate predictor of an important EAF thickness (HR 1.01; 95%CI 1.001–1.026; P = 0.04). BMI was not associated to EAF. Hypertension and EAF thickness (HR 5.71; 95%CI 1.22–26.75; P = 0.009; HR 1.41; 95%CI 1.09–1.84; P = 0.009 respectively) were independent predictive factors of LA enlargement whereas glomerular filtration rate was protective (HR 0.95; 95%CI 0.92–0.99; P = 0.010). We could not identify LARR predictor except ACEI/ARB treatment (HR 2.78; 95%; CI 1.023–7.597; P = 0.044). No significant decrease of EAF could be observed in LARR+ and LARR- groups. Conclusion LA volume was the sole independent predictor of EAF thickness. Hypertension, EAF thickness were associated with LA enlargement. ACEI/ARB was predictive of LARR. No significant decrease in EAF thickness was associated with reverse remodeling after AF ablation.