The improvement of endothelial function by inhibition of platelet activity using acetylsalicylic acid in patients with arterial hypertension
Authors:   M. D. Strazhesko National Scientific Center of Cardiology, Clinical and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, Ukraine, Talaieva Tatyana , Mishchenko Larysa , Tretyak Iryna , Matova Olena , Vasilinchuk Natalia , Vavilova Larysa 
Published: November 2023

In accordance with modern ideas about the pathogenesis of thrombotic complications of cardiovascular diseases (myocardial infarction, stroke), it should be noted that platelets and platelet humoral factors play a key role in the development of thrombosis. Activated platelets are able to activate both endotheliocytes and pro-inflammatory cells - monocytes/macrophages, which take a direct part in the formation and progression of atherosclerotic plaque. The purpose of the study is to investigate the potential improvement of endothelial function through the inhibition of platelet activity using acetylsalicylic acid in patients with arterial hypertension and established atherosclerotic cardiovascular diseases. Materials and methods. We enrolled 41 patients with arterial hypertension and established atherosclerotic cardiovascular diseases in our study. The participants were divided into two groups. Group 1 comprised 20 patients who were already taking acetylsalicylic acid (ASA) before the study, while Group 2 consisted of 21 patients who had not received ASA before participating. During the 6-month study period, patients from both groups received ASA (75 mg once a day) as part of their basic therapy, which included antihypertensive and statin therapy. Platelet activity was assessed in all patients before the study and at the final stage by determining the expression of glycoproteins GPIIb-IIIa and P-selectin on their surface. Additionally, the content of endothelial progenitor cells (phenotype CD45-CD31+CD133+) and desquamated endothelial cells (phenotype CD45-CD31+CD133-) in the blood was analyzed using flow cytometry. ELISA was employed to measure the content of C-reactive protein, cytokines TNF-α and IL-10, as well as asymmetric dimethylarginine (ADMA) in the blood. Finally, all patients underwent a test with flow-dependent vasodilation of the brachial artery. Results. In patients who did not receive ASA before the study, there was a higher level of platelet activity in peripheral blood flow, along with signs of more pronounced endothelial dysfunction compared to those who received it. After 6 months of taking ASA alongside standard antihypertensive therapy, the activation level of circulating blood platelets decreased in both groups. Specifically, in patients of group 1, the expression level of CD41 (GPIIb) decreased by 31.8 % (p < 0.01), and CD61 (GPIIIa) decreased by 15.2 % (p < 0.01). In group 2 patients, the suppression of platelet activity was even more pronounced, with the expression level of CD41 (GPIIb) decreasing by 55.2 % (p < 0.001), and CD61 (GPIIIa) decreasing by 27.5 % (p < 0.05). Furthermore, in patients of group 1, the percentage of platelets carrying P-selectin on the surface decreased by 78.1 % (p < 0.01). In group 2, the number of such platelets also significantly decreased by 42.5 % (p < 0.05). The number of progenitor cells of endothelial cells in the circulating blood increased significantly in both groups, showing a 3-fold increase in patients of group 1 (p < 0.001) and a 2.3-fold increase in patients of group 2 ( p< 0.001). In patients of both groups, a significant 2-fold increase in the endothelium-dependent vasodilatation index was observed (p < 0.01). At the end of the study, there was a decrease in the blood level of CRP by 12.2 % and 18.8 %, and pro-inflammatory cytokine TNF-α decreased by 50% and 57 %, respectively, in patients of groups 1 and 2 (p < 0.001). Conclusion. The reduction in blood platelet activity triggered by ASA in patients with arterial hypertension and atherosclerotic cardiovascular diseases was associated with notable alterations in the intensity of systemic inflammation and the restoration of endothelial functions. These findings suggest a potential therapeutic role for ASA in modulating both platelet function and endothelial health in individuals with these conditions.