Epicardial adipose tissue thickness and ablation outcome of atrial fibrillation.

OBJECTIVES: Epicardial fat was closely related to atrial fibrillation (AF). Transthoracic echocardiography (TTE) has been proposed to be a convenient imaging tool in assessing epicardial adipose tissue (EAT). The goal of the present study was to investigate whether the EAT thickness measured on TTE was a useful parameter in predicting procedural outcomes of AF ablations. METHODS AND RESULTS: A total of 227 paroxysmal AF (PAF) and 56 non-paroxysmal AF (non-PAF) patients receiving catheter ablations from 2008-2010 were enrolled. Echocardiography-derived regional EAT thickness from parasternal long-axis view was quantified for each patient. Free of recurrence was defined as the absence of atrial arrhythmias without using antiarrhythmic agents after ablations. The mean EAT thickness of the study population was 6.1 ± 0.8 mm. Non-PAF patients had a thicker EAT than that of PAF patients (7.0 ± 0.7 mm versus 5.9 ± 0.7 mm, p value <0.001). During the follow-up of 16 ± 9 months, there were 95 patients (33.6%) suffering from recurrences of atrial arrhythmias. Non-PAF, chads2 score, left atrial diameter and EAT thickness were independent predictors of recurrence after catheter ablations. At a cutoff value of 6 mm for PAF and 6.9 mm for non-PAF, the measurement of EAT thickness could help us to identify patients at risk of recurrences. CONCLUSIONS: EAT thickness may serve as a useful parameter in predicting recurrences after AF ablations. Compared to other imaging modalities, TTE can be an alternative choice with less cost and time in assessing the effects of EAT on ablation outcomes

ROC curve and Kaplan-Meier analysis of EAT thickness in predicting recurrence after catheter ablation of PAF.

<p>At the cutoff value of 6.0 mm identified by the ROC curve (A), PAF patients with an EAT thickness of > 6.0 mm had a higher recurrence rate of atrial arrhythmias after catheter ablation (B). EAT = epicardial adipose tissue; PAF = paroxysmal atrial fibrillation; ROC = receiver-operator characteristic.</p

ROC curve and Kaplan-Meier analysis of EAT thickness in predicting recurrence after catheter ablation of non-PAF.

<p>At the cutoff value of 6.9 mm identified by the ROC curve (A), non-PAF patients with an EAT thickness of > 6.9mm had a higher recurrence rate of atrial arrhythmias after catheter ablation (B). EAT = epicardial adipose tissue; PAF = paroxysmal atrial fibrillation; ROC = receiver-operator characteristic.</p

Differences of EAT thickness in PAF and non-PAF patients and those with and without recurrences.

<p>Increased EAT thickness was noted among non-PAF patients and those who experienced recurrences after catheter ablation. EAT = epicardial adipoes tissue; PAF = paroxysmal atrial fibrillation. +P value < 0.05, non-PAF versus PAF patients; *P value < 0.05, patients with recurrences versus patients without recurrences.</p

Measurement of EAT.

<p>The thickness of EAT measured in parasternal long-axis view of TTE (A) and 3-chamber view of CT with contrast enhancement (B) showed significant correlation (C). AO = aorta; CT = computed tomography; EAT = epicardial adipose tissue; LA = left atrium; LV = left ventricle; RV = right ventricle; TTE = transthoracic echocardiography.</p