Association of inflammatory and oxidative markers with low voltage areas and atrial fibrillation recurrence in left atrial mapping

Atrial fibrillation (AF) is commonly treated with catheter ablation, yet inflammation and oxidative stress markers like C-reactive protein (CRP) and NOX2 have been associated with both the extent of atrial myocardial injury and AF recurrence. Elevated levels of these markers not only reflect the body’s inflammatory response but also contribute to atrial structural remodelling, potentially increasing the risk of recurrent arrhythmias. Recent studies suggest that persistent inflammation and oxidative stress can exacerbate atrial fibrosis, creating low voltage areas (LVAs) that serve as substrates for AF. (1) (2) Identifying correlations between CRP, NOX2, and LVAs may help in predicting patient outcomes post-ablation. By exploring these associations, this study aims to provide insights into the role of inflammation and oxidative stress in AF recurrence and assess their potential as biomarkers for procedural success.

This prospective study enrolled 104 patients with paroxysmal AF undergoing first time pulmonary vein isolation (PVI) with a QDOT ablation catheter. High-density mapping of the left atrium was performed using a Pentaray catheter, identifying low voltage areas with a threshold of <0.05 mV. Blood levels of patients' CRP and NOX2 levels were measured before ablation and at 3 months follow-up. AF recurrence was assessed with 24 hours Holter ECG.

In the study, 59 patients with at least one low voltage area greater than 1 cm² (<0.05 mV) had a baseline CRP level of 0.7±0.30. This level decreased to 0.3±0.1 at the 3-month post-ablation follow-up (P<0.001). In contrast, for the 45 patients without any areas <0.05 mV, baseline CRP was 0.2±0.1, remained at 0.2±0.3 at 3 months post-ablation (P>0,05).

Additionally, within the 12-month follow-up period, 18 out of 59 patients with low voltage areas experienced AF recurrence, while only 5 out of 45 patients without low voltage areas had a recurrence (P Value<0,002).

Elevated CRP and NOX2 levels are strongly associated with larger low voltage areas in the left atrium and a higher risk of AF recurrence. These findings suggest that inflammatory and oxidative stress markers could serve as valuable predictors of atrial remodeling and procedural outcomes in AF ablation.

a wide anterior low voltage area