Impact of Inflammation-mediated Myocardial Fibrosis on the Risk of Recurrence After Successful Ablation of Atrial Fibrillation - the FIBRO-RISK Study

The prevalence of atrial fibrillation (AF) is on the rise, being the most frequent sustained supraventricular arrhythmia and a health issue by its increased morbidity and mortality. In most of the cases, myocardial tissue located at the level of the pulmonary veins represents the trigger for atrial fibrillation. The pathophysiology of AF is still incompletely understood, several studies suggesting that profibrotic and inflammatory processes have a crucial role in the development of AF. So far the success rate of AF ablation is not very high, reaching 70% in patients with paroxysmal AF and 50% in cases with persistent AF. Several risk factors for the occurrence and recurrence of AF have been described in the literature, including left atrial enlargement, left ventricular dysfunction, epicardial fat volume, and myocardial fibrosis caused by local atrial inflammation. What remains to be investigated is the relationship between these risk factors and the recurrence of AF after radiofrequency catheter ablation using advanced 3D mapping system.

This is a clinical prospective, descriptive, single-center study which will be carried out in the Center of Advanced Research in Multimodal Cardiac Imaging Cardiomed Tirgu Mures, Romania. The duration of the study is 2 years which include the initial screening and the follow-up period for the recurrence of AF.

The study will include 100 subjects suitable for catheter ablation. Imaging biomarkers and laboratory analyses such as high sensitive C Reactive Protein (hsCRP), matrix metalloproteases (MMP), interleukin-6 (IL6) and N-Terminal Pro-B-Type Natriuretic Peptide (NT pro-BNP) will be determined in the first 24 hours after the procedure. The anatomy of pulmonary veins, atrial fibrosis, atrial volumes and the amount of epicardial fat will be evaluated and quantified with late gadolinium-enhancement cardiac magnetic resonance (LGE-CMR). All these parameters will be investigated in patients with successful ablation of AF, who will be divided into 2 groups: group 1 - patients who develop AF recurrence at 1-year, and group 2 - patients with no recurrence of AF at 1-year. In all patients, the following biomarkers will be determined: serum levels of inflammatory biomarkers and NT-proBNP at 24 hours and 1 year post-procedure, the amount of myocardial fibrosis at the level of left atrium and left ventricle at baseline +/- 7 days and the amount of epicardial fat surrounding left atrium, right atrium and the entire heart at baseline +/- 7 days.

The study will be conducted over a period of 2 years, in which patients will be examined at baseline, and will be followed-up for recurrence of AF.

All patients will sign an informed written consent and will be checked for the exclusion criteria prior to enrolment.