Endothelial Function And Platelet Activation In Patients With Non-valvular Atrial Fibrillation And The Influence Of Beta-blocker On Them

[Background]Atrial fibrillation is a common persistent arrhythmia, which occurs more apparently with age increasing. Atrial fibrillation may result in thrombogenesis and systemic embolization( especially the stroke). Platelet activation is one of the reasons for the prothrombotic state. Raised serum von Willebrand Factor(vWF, a marker of endothelial damage) and soluble P-selectin(sP-sel, an index of platelet activation) are often found in patients with cardiovascular diseases. Recent studies showed an activation/damage in endothelial cell( EC) system and platelet activation in patients with atrial fibrillation, which was represented by increased serum vWF and sP-sel levels. Taking beta-blocker as an rate control strategy is common in atrial fibrillation, but its benefit out of rate control is still not clear.[Objectives]1.To examine serum von Willebrand factor and soluble P-selectin levels in patient with non-valvular atrial fibrillation. To investigate the relationship between levels of the two factors and atrial fibrillation(AF).2.To evaluate the influence of Beta-blocker on vWF and sP-sel levels. 3.To investigate the predictors of serum vWF and sP-sel levels.[Methods]Twenty-five subjects(mean age 71.78±7.21 years), 16males and 8 females, with persistent non-valvular atrial fibrillation and left ventricular ejection≥50% were enrolled as AF group. Those with myocardial infarction, cardiomyopathy or hyperthyriodism were excluded. Control group (34 subjects, age, sex, left ventricular ejection paired with AF group) were patients with sinus rhythm and similar cardiovascular diseases as AF group. Serum vWF and sP-sel levels were tested by ELASA assay.[Results]Patients with AF had significantly higher plasma levels of vWF(1948.5±l 14.2ng/ml) compared with control group (1861.5±101.9ng/ml) (P=0.04). However, there was no significant difference of serum sP-sel level between AF group(24.33±9.35ng/ml)and control group(24.55±11.13ng/ml).After administrated with beta-blocker, a down regulation was found in serum vWF level (1748.5±155.6ng/ml, P<0.01) but not in sP-sel level(21.33±9.07ng/ml, P=0.06).There was no relationship between serum level of vWF, sP-sel and age, heart rate, left appendage size et al.[Conclusions ]1 .High level of serum vWF was found in patients with persistent non-valvular atrial fibrillation, indicating endothelial damage/dysfunction in those patients.2. After administrates with beta-blocker, serum level of vWF dropped dramatically in patients with AF, indicating possible function of endothelial protection of beta-blocker.3.No evidence of association was found between serum level of vWF, sP-sel and age, heart rate, left appendage size et al.