AUTHOR=Chahine Yaacoub , Askari-Atapour Bahareh , Kwan Kirsten T. , Anderson Carter A. , Macheret Fima , Afroze Tanzina , Bifulco Savannah F. , Cham Matthew D. , Ordovas Karen , Boyle Patrick M. , Akoum Nazem 

TITLE=Epicardial adipose tissue is associated with left atrial volume and fibrosis in patients with atrial fibrillation

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.1045730

DOI=10.3389/fcvm.2022.1045730

ISSN=2297-055X

ABSTRACT=<sec><title>Background</title><p>Obesity is a risk factor for atrial fibrillation (AF) and strongly influences the response to treatment. Atrial fibrosis shows similar associations. Epicardial adipose tissue (EAT) may be a link between these associations. We sought to assess whether EAT is associated with body mass index (BMI), left atrial (LA) fibrosis and volume.</p></sec><sec><title>Methods</title><p>LA fibrosis and EAT were assessed using late gadolinium enhancement, and Dixon MRI sequences, respectively. We derived 3D models incorporating fibrosis and EAT, then measured the distance of fibrotic and non-fibrotic areas to the nearest EAT to assess spatial colocalization.</p></sec><sec><title>Results</title><p>One hundred and three AF patients (64% paroxysmal, 27% female) were analyzed. LA volume index was 54.9 (41.2, 69.7) mL/m<sup>2</sup>, LA EAT index was 17.4 (12.7, 22.9) mL/m<sup>2</sup>, and LA fibrosis was 17.1 (12.4, 23.1)%. LA EAT was significantly correlated with BMI (<italic>R</italic> = 0.557, <italic>p</italic> &lt; 0.001); as well as with LA volume and LA fibrosis after BSA adjustment (<italic>R</italic> = 0.579 and <italic>R</italic> = 0.432, respectively, <italic>p</italic> &lt; 0.001 for both). Multivariable analysis showed LA EAT to be independently associated with LA volume and fibrosis. 3D registration of fat and fibrosis around the LA showed no clear spatial overlap between EAT and fibrotic LA regions.</p></sec><sec><title>Conclusion</title><p>LA EAT is associated with obesity (BMI) as well as LA volume and fibrosis. Regions of LA EAT did not colocalize with fibrotic areas, suggesting a systemic or paracrine mechanism rather than EAT infiltration of fibrotic areas.</p></sec>