Systemic markers of inflammation and immune activation in patients with obstructive sleep apnea and paroxysmal atrial fibrillation.

Background: Atrial fibrillation (AF) and obstructive sleep apnea (OSA) frequently coexist, contributing to cardiovascular risk, possibly through shared inflammatory pathways. The specific role of inflammatory markers in patients with AF and OSA is not well established.

Aim: This study aimed to determine whether markers of inflammation and immune activation are elevated in patients with paroxysmal AF and OSA, assess the effects of continuous positive airway pressure (CPAP) and pulmonary vein isolation (PVI) on these markers, and evaluate their association with clinical outcomes, such as AF recurrence and thromboembolic risk.

Methods: We studied 143 patients with paroxysmal AF and moderate to severe OSA (apnea-hypopnea index ≥15). Of these, 99 were randomised to receive CPAP plus standard care (n = 51) or standard care alone (n = 48). A comparison group of 19 patients with paroxysmal AF and mild/no OSA (AHI <15) and 22 healthy controls were also included. Inflammatory markers related to leukocyte activation, vascular inflammation, and extracellular matrix remodelling were assessed at baseline, 6 months and 12 months follow-up.

Results: Patients with OSA and paroxysmal AF had higher levels of NGAL, PTX-3, GDF-15, MMP-9, VCAM1 and ANGP2 than healthy controls. These markers correlated poorly with AF and OSA severity. There was no modifying effect of CPAP on any marker. PTX3 was associated with AF recurrence and a high-risk score for thromboembolic stroke.

Conclusion: Moderate to severe OSA and AF are associated with elevated inflammatory markers. However, CPAP therapy did not significantly affect these levels. PTX-3 may hold prognostic value for AF recurrence and thromboembolic risk.