Background: Atrial fibrillation (AF) is associated with a prothrombotic state, which is related to endothelial damage/dysfunction. Plasma levels of soluble E-selectin (sE-sel), von Willebrand factor (vWf), and soluble thrombomodulin (sTM) have been used as indexes of endothelial activation, damage/dysfunction, and endothelial damage, respectively. Nitric oxide is also made by a healthy endothelium, and a total body nitrate/nitrite product (NOx) is used as a measure of endothelial nitric oxide production. We hypothesized that the levels of these markers of endothelial function would be abnormal in patients with paroxysmal, persistent, and permanent AF.
Methods: We studied 145 AF patients (paroxysmal AF, 35 patients; permanent AF, 50 patients; persistent AF, 60 patients) and 35 patients with "lone" AF. Plasma levels of sE-sel, vWf, and sTM (measured by enzyme-linked immunosorbent assay) and NOx (measured by a colorimetric assay based on the Griess reaction) were compared to 40 age-matched healthy control subjects in sinus rhythm.
Results: Patients with AF had significantly higher plasma levels of vWf (p < 0.001) and sE-sel (p = 0.005) compared with control subjects, but sTM and NOx levels were not significantly different. Levels did not differ significantly among the clinical subgroups of patients with paroxysmal, persistent, and permanent AF. Patients with lone AF had significantly higher vWF levels (p = 0.003) and significantly lower sTM levels (p = 0.0361) compared to control subjects, but sE-sel and NOx levels were not significantly different. There were no significant differences in the AF study population in vWF, sE-sel or sTM levels after 4 weeks of warfarin treatment.
Conclusion: Endothelial perturbation exists in all clinical subgroups of patients with AF, including those with lone AF, which may contribute to the prothrombotic state seen in these patients.