Structural Cardiac Remodeling in Atrial Fibrillation

Area of Science:

• Cardiology
• Medical Imaging
• Electrophysiology

Background:

• Atrial remodeling is a key factor in the development and persistence of atrial fibrillation (AF).
• Anatomical imaging features are increasingly recognized for their role in influencing atrial remodeling and AF substrate.
• Understanding these features is crucial for predicting AF recurrence post-ablation.

Purpose of the Study:

• To evaluate preablation computed tomography angiography (CTA) for atrial and epicardial features.
• To determine the predictive value of these features for atrial fibrillation (AF) recurrence after ablation therapy.
• To assess the association between specific anatomical characteristics and AF recurrence.

Main Methods:

• Cardiac CTA was performed on patients with nonvalvular AF before pulmonary vein isolation.
• Evaluated parameters included left and right atrial volumes, left atrial wall thickness (LAWT), and epicardial adipose tissue (EAT) volume and attenuation.
• Follow-up included clinical assessment and repeated CTA studies; electroanatomical mapping subanalyses were also conducted.

Main Results:

• AF recurrence was observed in 36.9% of patients.
• Higher indexed LA volume, increased LAWT (anterior and posterior), and greater EAT volume were associated with AF recurrence.
• Lower EAT attenuation (higher lipid content) and specific atrial voltage map characteristics also predicted recurrence.
• Adding LAWT to established risk models significantly improved prediction (NRI = 0.279).

Conclusions:

• Atrial wall thickness, epicardial fat volume, and attenuation are significant predictors of AF recurrence.
• Preablation CTA provides valuable insights into structural atrial changes and epicardial fat characteristics.
• These imaging biomarkers can enhance risk stratification for AF recurrence following ablation.