Spontaneous and stimulated platelet aggregation activity in patients with atrial fibrillation and thrombotic complications

Abstract

Aim: To study spontaneous and stimulated by adenosine diphosphate (ADP), adrenaline and collagen platelet aggregation activity, CD40-CD40 ligand system in patients with atrial fibrillation (AF) with previous thromboembolic complications (TEC) and newly diagnosed thrombosis.Material and Methods. The study included patients with «non-valvular» AF and anamnesis of TEC and newly identified thrombosis on anticoagulants in the period 01.2020-01.2023: 13 patients had anamnesis of TEC (group 1), in 18 patients were initially diagnosed thrombosis/spontaneous atrial echocontrast of high grade (group 2). The comparison group was the healthy individuals (n = 31) (group 3). The spontaneous aggregation ability of platelets and stimulated with solutions of ADP, adrenaline and collagen, the level of CD40 markers, soluble CD40 ligand (CD40L) were studied.Results. The spontaneous platelet aggregation activity was significantly higher in patients of group 2 compared with healthy individuals with a formation trend of larger aggregates in patients with TEC. When aggregation was induced by collagen, the rate of aggregate formation was significantly lower in the 1st and 2nd groups compared with healthy individuals. When using ADP, a comparable decrease in the degree and speed was noted, and when using adrenaline, only the rate of platelet aggregation was observed in groups 1 and 2. The concentration of soluble CD40L was significantly higher in patients with a history of TEC and newly thrombosis.Conclusion. Spontaneous platelet aggregation activity and the concentration of soluble CD40L are increased both in patients with past of TEC and in patients with newly diagnosed thrombosis due to AF and anticoagulant monotherapy.