Atrial fibrillation modifies the association between CT-derived epicardial adipose tissue volume and left atrial remodeling in valvular heart disease.

BACKGROUND

Epicardial adipose tissue volume (EATv) is associated with atrial fibrillation (AF), but whether AF modifies the association between EATv and atrial remodeling in valvular heart disease remains unclear.

OBJECTIVE

To determine whether AF modifies the association between computed tomography (CT)-derived EATv and left atrial remodeling.

METHODS

This retrospective valvular surgery cohort included 436 patients (218 with AF and 218 with sinus rhythm [SR]) after 1:1 propensity score matching. Multivariable linear and logistic regression analyses assessed the associations of EATv with left atrial volume index (LAVI) and left atrial enlargement (LAE). Restricted cubic spline, receiver operating characteristic curve, and mitral regurgitation-stratified sensitivity analyses were performed. Exploratory histology and EAT secretome analyses were conducted in surgical samples.

RESULTS

Patients with AF had higher EATv and larger atria than those with SR. In the primary adjusted model, each 10 cm3 increase in EATv was associated with a 1.21 mL/m2 higher LAVI in SR and a 4.45 mL/m2 higher LAVI in AF (P for interaction = .002). EATv was associated with LAE (odds ratio, 1.29; 95% confidence interval, 1.17-1.43), with a significant AF-by-EATv interaction (odds ratio, 1.41; 95% confidence interval, 1.15-1.74). Adding EATv improved discrimination for LAE (area under the receiver operating characteristic curve [AUC], 0.767-0.804; P = .007). Exploratory tissue analyses suggested adipocyte hypertrophy, fibrosis, and reduced Wnt-antagonist secretion in AF-associated EAT.

CONCLUSION

Higher CT-derived EATv was associated with more advanced left atrial remodeling, with stronger associations in AF than in SR. EATv may serve as a CT-derived marker of remodeling vulnerability in valvular heart disease.