Clinical Electrophysiology -> Atrial Fibrillation & Atrial Flutter: -> Physiology D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-018 - Atrial Fibrosis Progression In Individuals With No History Of Atrial Fibrillation (ID 45)

 L. Dagher: Nothing relevant to disclose.


Background: Unexpected high levels of atrial fibrosis are found even in non-atrial fibrillation (AF) individuals. However, data are limited regarding the progression of atrial fibrosis in this population.
Objective: We aim to analyze the progression of fibrosis in individuals with no history of atrial fibrillation.
Methods: Non-AF subjects (n=42) with no structural heart disease underwent a baseline and one to two-year delayed enhancement magnetic resonance imaging (DE-MRI) for evaluation of atrial fibrosis progression. Patients were assessed for AF incidence using holter monitoring at 3,6, and 12 months.
Results: All patients (27 male, 65.9 ± 8.6 years old) had a detectable level of left atrial (LA) fibrosis at baseline, ranging from 4.5% to 28.8%, with a mean of 12.9±5.9%. At follow up DE-MRI, the degree of change in atrial fibrosis ranged from 0.10% to 27%. Fibrosis in the second DE-MRI was significantly higher in all patients compared to the first one (mean value of 12.9±5.9% vs. 17.34±6.8%; p <0.05). Seven patients (16.6%, 3 males; 68.1±4.5 years) developed a new-onset AF during follow up period. Interestingly, they showed a significantly higher degree of LA fibrosis in their second MRI, compared to those who stayed in sinus rhythm (SR) (20.5±6.9% vs. 16.7±6.7%, p<0.05).
Conclusion: From our preliminary data, LA fibrosis is a dynamic process that is prevalent and progressively increasing even in non-AF individuals with no apparent heart disease. The fact new onset AF patients showed a higher LA fibrosis progression could highlight the fact that AF is a manifestation of a highly dynamic atrial substrate, or the concept that AF begets fibrosis.