Molecular mechanisms of postoperative atrial fibrillation in patients with obstructive sleep apnea

Abstract

Obstructive sleep apnea (OSA) promotes atrial remodeling and fibrosis, providing a substrate for atrial fibrillation (AF). Herein, we investigate the pathophysiological mechanisms of AF in association with OSA in a cohort of cardiac surgery patients. A prospective study including patients undergoing cardiac surgery. Biomarkers reflective of AF pathophysiology (interleukin [IL-6], C-reactive protein [CRP], von Willebrand factor [vWF], N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity Troponin T [hs-TnT], and Galectin-3 [Gal-3]) was assessed by functional or immunological assays. miRNAs involved in AF were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Using atrial tissue samples, fibrosis was assessed by Masson's trichrome. Connexin 40 and 43 (Cx40; Cx43) were evaluated by immunolabeling. Fifty-six patients (15 with OSA and 41 non-OSA) were included in this hypothesis-generating pilot study.OSA group had a higher incidence of postoperative AF (POAF) (46.7% vs. 19.5%; p = .042), presented an increased risk of POAF (OR 3.61, 95% CI 1.01-12.92), and had significantly higher baseline levels of NT-proBNP (p = .044), vWF (p = .049), Gal-3 (p = .009), IL-6 (p = .002), and CRP (p = .003). This group presented lower

The Heart Beats as It Breathes, or Is It the Other Way Around?

“…The pathophysiological mechanisms of atrial fibrillation (AF) in patients with obstructive sleep apnoea are detected by using atrial tissue samples and assessment of several biomarkers. It is found that dysregulated miRNA, interstitial fibrosis and Connexins expression create the substrates of electro-anatomical disarrangement linked to higher risk of AF [ 4 ], the most common arrhythmias affecting cardiac patients above all over the age of fifty. Several aspects need to be considered in the pathogenesis of AF onset and its maintenance, traceable not only to atrial fibres disarray, cardiovascular risk factor (diabetes, atherosclerosis, chronic renal failure) or extracardiac noxa such as nightly hypoxemia.…”