Epicardial Fat and Atrial Fibrillation: the Role of Profibrogenous Mediators

Mari G. Arakelyan, Elena Z. Golukhova, Olga I. Gromova, Naida I. Bulaeva, Tatiana V. Mashina, Violetta S. Dzhanketova, Aygerim Z. Zholbaeva, Maria A. Shlyappo

A.N. Bakoulev Scientific Center for Cardiovascular Surgery, Moscow, Russia

Date, time and location: 2018.05.25 13:30, Exhibition area, 1st Floor. Zone – A

Abstract

Background. Epicardial fat(EF) has certain paracrine functions, which could be associated with

proinflammatory and fibrotic changes in myocardium even in patients without structural heart

disease but atrial fibrillation(AF). Though pathophysiological mechanisms are not clear enough.

The most valid methods of EF assessment are cardiac magnetic resonance imaging(MRI) and

computed tomography(CT).

Purpose. To evaluate the correlates between clinical data, parameters of tissue Doppler imaging

(TDI), EF thickness by MRI and biochemical markers of fibrosis and inflammation in patients

with nonvalvular AF without concomitant coronary artery disease(CAD) with normal or slightly

enlarged left atria (LA).

Methods. In our study were enrolled 166 patients with AF. This subanalysis included 39 patients

with idiopathic AF with normal or slightly enlarged left atria (LA) (mean LA diameter

4,5±0,6cm). The mean age was 50,8±13,9 y.o., 19 (49%) were men. The absence of coronary

lesions was confirmed by angiography in all cases. Besides standard ECG and ECHO, all

patients underwent TDI and cardiac MRI with late gadolinium enhancement. The myocardial

fibrotic and proinflammatory biomarkers levels-matrix metalloproteinases (MMP-2, MMP-9),

tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were estimated.

Results. The epicardial fat thickness at anterior left ventricular (LV) wall was associated with

TIMP-1 plasma level (τ=0,71; Тcr=0,18). The significant correlation between fat thickness and

MMP-9 was defined (τ=0,65; Тcr=0,16). Among clinical factors weight was slightly associated

with fat thickness (τ=0,33; Тcr=0,26). Besides, we found correlation of MMP-9, TIMP-1 with

E/e’ by TDI (τ=0,65; Тcr=0,16 and τ=0,56; Тcr=0,21, relatively); and with maximal systolic

strain of lateral LV wall (τ=-0,37; Тcr=0,18 and τ=-0,44; Тcr=0,16, relatively) and

interventricular septum (τ=-0,36; Тcr=0,18 and τ=-0,44; Тcr=0,16, relatively).

Conclusion. The epicardial fat thickness by MRI is significantly associated with myocardial

fibrosis markers (MMP-9, TIMP-1) in patients with AF without structural heart disease. The

increasing levels of MMP-9 and TIMP-1 are associated with LV local contractility disturbances

by TDI in patients with AF, which could reflect initial presentation of atrial cardiomyopathy

even in patients with nonvalvular “nonischemic” AF with normal or slightly enlarged LA.