Prognostic model of the risk of gastroduodenal bleeding in COVID-19 patients with morphometric assessment of factors contributing to vascular wall remodeling

In the pathogenesis of hemorrhagic syndrome in COVID-19, on the one hand, the development of heparin-induced coagulopathy cannot be excluded, on the other hand, the development of critical conditions accompanied by the release of proinflammatory factors into the bloodstream may occur. SARS-CoV-2 – associated endotheliopathy is considered as an additional link in the pathological process. At the same time, during the diagnostic process, it becomes necessary to identify markers that contribute to the development of gastrointestinal bleeding. The aim of the study was to determine the main risk factors for gastrointestinal bleeding in COVID-19 patients based on a comprehensive clinical, laboratory and instrumental examination, as well as to analyze the effectiveness of hemostasis methods in patients with gastroduodenal bleeding. The study involved 332 patients with COVID-19 and developed gastrointestinal bleeding. When creating a prognostic model using logistic regression with the ROC-curve construction, a correlation was established between the development of gastrointestinal bleeding and the level of APTT, D-dimer, the degree of lung parenchymal involvement according to CT, history of cardiac rhythm disorders, and the method of providing respiratory support (р 0,05). An immunohistochemical investigation using monoclonal antibodies to CD31, CD34, CD68 and vWF receptors expressed on the endothelial surface revealed an alteration of the endothelial monolayer, contributing to the occurrence of a hemorrhagic event. Thus, an increase in the frequency of gastrointestinal bleeding in COVID-19 patients is directly related to the direct cytopathic effect of the SARS-CoV-2 on endotheliocytes (destruction of the vascular wall due to degradation of the endothelial layer). Based on a model constructed by binary logistic regression, a prognostic risk scale for the development of gastroduodenal bleeding from the upper gastrointestinal tract in patients with COVID-19 was created (Eurasian Patent for Invention No. 047178 dated 06.17.2024). The sensitivity of the method was 64.3%, specificity 72.1%, accuracy 68%. The risk scale for the development of gastroduodenal bleeding from erosive and ulcerative mucosal defects in patients with COVID-19 is a highly informative method that allows to predict hemorrhagic events in a timely manner. Also, the effectiveness of combined hemostasis methods in patients with gastrointestinal bleeding has been confirmed.