The purpose of this study was to determine whether there are any differences in the levels of inflammatory, thrombotic, and collagen turnover biomarkers between individuals with atrial fibrillation (AF) and healthy volunteers. Circulating plasma levels of plasminogen activator inhibitor 1 (PAI-1), CD40-ligand (CD40-L), nucleosomes (which are indicators of cell death), C-reactive protein (CRP), procollagen III N-terminal propeptide (PIIINP), procollagen III C-terminal propeptide (PIIICP), procollagen I N-terminal propeptide, tissue plasminogen activator, and von Willebrand factor were analyzed as potential biomarkers of AF. Baseline plasma was collected from patients with AF prior to ablation surgery at Loyola University Medical Center. Individuals with AF had statistically significantly increased levels of PAI-1, CD40-L, and nucleosomes, when compared to the normal population ( P < .0001). Additionally, there was a statistically significant increase in the CRP ( P = .01), PIIINP ( P = .04), and PIIICP ( P = .0008) when compared to normal individuals. From this study, it is concluded that the prothrombotic, inflammatory, and collagen turnover biomarkers PAI-1, CD40-L, nucleosomes, CRP, PIIICP, and PIIINP are elevated in AF.

This study aims to examine the effects of atrial fibrillation (AF) on the expression of the cellular mediators plasminogen activator inhibitor 1 (PAI-1) and CD40 ligand (CD40-L). Additionally, the effect of catheter ablation on the levels of the aforementioned biomarkers was also examined. In this prospective study, plasma samples were collected from patients with AF at baseline prior to ablation and at 1 and 3 months postablation. There was a statistically significant increase in CD40-L at baseline in patients with AF compared to control ( P = .0034). There was a statistically significant decrease in CD40-L levels postablation at both 1 month ( P < .0001) and 3 months ( P < .0001) compared to baseline. Baseline levels of PAI-1 were elevated compared to the control group (mean 19.55 ± 2.17 ng/mL vs 4.85 ± 0.41 ng/mL) and a statistically significant decrease in circulating PAI-1 levels 1 month postablation ( P = .05) was noted compared to preablation levels. These data suggest that inflammation plays an important role in the pathogenesis of AF and that these cellular mediators are modulated by catheter ablation.

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Background: Oral anticoagulants such as warfarin have been conventionally used for the management of atrial fibrillation (AF). Despite the effectiveness of warfarin, its use in AF patients requiring anticoagulation is suboptimal with an even greater underuse seen in elderly patients who are at higher risk of stroke. New oral anticoagulants such as rivaroxaban(R), apixaban (A), dabigitran (D) and edoxaban (E) have been approved to manage thrombotic and cardiovascular disorders including AF. The newer anticoagulants do not require continuous monitoring like warfarin and are much more convenient for patients with AF. Objective: To profile the baseline level of circulating thrombotic biomarkers plasminogen activator inhibitor (PAI-1), von Willebrand Factor (vWF), microparticle bound tissue factor (MP-TF) and prothrombin fragment 1.2 (F1.2) in patients with AF. Additionally, the effect of novel oral anticoagulants (R, A, D and E) on the levels of thrombotic biomarkers in patients with AF is assessed. Materials and Methods: Citrated blood samples were drawn from 30 patients (21 male and 9 female; mean age 59.1) prior to ablation surgery for AF at Loyola University Medical Center in Maywood, Illinois. Citrated blood was spun at 3000 rpm to obtain platelet poor plasma. Normal plasma samples from healthy controls (24 male and 24 female; mean age 33) were purchased from a commercial source (George King Biomedical, Overland Park, KS). The plasma samples were analyzed using a biochip array (Randox, London, UK) for metabolic syndrome biomarkers including PAI-1 and ELISA kits for vWF, MP-TF (Hyphen BioMed, Nueville-Sur-Oise, France) and prothrombin F1.2 (Siemens, Newark, DE). Results: Compared to the control group, circulating levels of vWF, MP-TF and PAI-1 were statistically increased in patients with AF (P<0.0001, P<0.0001, and P=0.0014, respectively). Circulating levels of prothrombin F1.2 showed no difference between the AF and the control group (P=0.2696). AF patients (n=30) were divided into two groups based on their usage (Group 1, n=17) and non-usage (Group 2, n=10) of any novel oral anticoagulant (R, A, D and E). Three patients on warfarin were excluded from this section of data analysis. A statistical increase in vWF (P=0.0018) and MP-TF (P=0.0039) remained in those taking novel oral anticoagulants compared to group 2. No difference was seen in PAI-1 (P=0.333) or F1.2 (P=0.31) between groups 1 and 2. Percent change from the normal mean was also calculated for PAI-1, vWF, MP-TF and F1.2 in group 1 (78%, 61.1%, 142%, 8.9%, respectively) and group 2 (113.6%, 16.9%, 31.7%, 41.4%, respectively) as seen in table 1. Discussion: Elevated levels of PAI-1, vWF and MP-TF seen in AF patients compared to normal provide insight into an additional risk of thrombogenesis associated with AF which is not targeted by current anticoagulant medications. Most AF patients are assessed using a stroke risk stratification scale (CHA2DS2VASc) to determine if anti-coagulants should be used to prevent stroke associated with AF. Patients in group 1 had a mean CHA2DS2VASc score of 1.15 compared to 2.18 see in group 2. This data supports studies which suggest that including levels of prothrombotic biomarkers to current risk stratification scales could be more effective in assessing the risk of stroke of patients with AF. This data also suggests that although very effective in lowering prothrombin F1.2 levels in AF, the newer anticoagulants, R,A,D and E still leave additional prothrombotic biomarkers unaffected. These unaffected biomarkers could be the potential target of future drug therapies which could lower the risk of stroke in patients with AF even more than the use of newer anticoagulants alone. Disclosures No relevant conflicts of interest to declare.

Introduction : Atrial fibrillation (AF) is currently the most common cardiac arrhythmia encountered in clinical practice and a major cause of morbidity and mortality among adults. It is estimated that atrial fibrillation affects approximately 2.7 million people in the United States. Extracellular plasma nucleosomes (PNs) are complexes of DNA and histones that are released during cell death. Histones have been shown to function as DAMPs when they are translocated from the nucleus to the extracellular space. It is hypothesized that these extracellular nucleosomes contribute to the observed hypercoagulable state and embolic complications in AF. Methods : The concentration of PNs in 48 plasma samples of atrial fibrillation patients and 38 aged-matched controls were measured using the Cell Death Detection ELISA PLUS assay (Roche Diagnostics, Mannheim, Germany) and functional microparticle levels were measured using an annexin binding method (Hyphen Biomedical, Paris, France). Results : When comparing the concentration of nucleosomes in plasma, the atrial fibrillation patients (306.1 ± 328.86 μg/mL) had much higher levels than the aged-matched controls (177.9 ± 146.7 μg/mL), (p = 0.0015). Functional microparticles were also markedly elevated in the AF patients (18.6 ± 4.1 nM) in comparison to the aged-matched controls (4.6 ± 3.1 nM), (p=0.001). A significant correlation was observed between the PN's and microparticles, (p < 0.05). Conclusion : Both the microparticles and PNs were elevated in atrial fibrillation when compared to aged-matched controls, suggesting increased cell death resulting in the generation of these biomarkers. Extracellular nucleosomes function as DAMPs by binding to receptors and triggering the activation of multiple signal pathways which may contribute to the elevation of microparticles. Due to the involvement of inflammation and thrombosis in the pathology of atrial fibrillation, the simultaneously increased circulating nucleosome and microparticle levels in patients with AF implies their role in the pathogenesis of this syndrome. Disclosures No relevant conflicts of interest to declare.