Integral and Local Methods for the Evaluation of the Hemostasiological Profile in Sheep at Various Stages of Implantation of a Biodegradable Vascular Graft.

The aim of this study was to evaluate the efficiency of local and integral methods of the assessment of the hemostasiological profile in sheep at various stages of implantation of a biodegradable vascular graft. Materials and Methods: The object of the study was the whole blood of sheep collected at the stage of premedication, during the intraoperative period, and in the early postoperative period. Thromboelastography was used to assess the kinetics of clot formation and changes in its viscoelastic properties in whole blood samples. The thrombin generation test was performed in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) with the assessment of quantitative and temporal parameters. The platelet factor 4 concentration in PRP and PPP was measured by the enzyme immunoassay. The functional activity of platelets in PPP was assessed with inductors and without additional stimulation. Prothrombin complex activity, APTT values, thrombin time, fibrinogen concentration, antithrombin III and protein C activity, soluble fibrin monomer complexes, and fibrinolysis were determined in blood plasma. Results: Multidirectional changes in the hemostasiological profile at various stages of vascular prosthesis implantation have been revealed. On the one hand, it is an increased prothrombogenic status, on the other hand, it is the development of hypocoagulation. Shortening of the R (blood coagulation time) and K (clot formation time) intervals and an increase in the angle parameter and maximum amplitude on the thromboelastogram in all the studied periods relative to the reference values, a significant increase in platelet factor 4 in PRP and increased platelet aggregation testified in favor of hypercoagulation. However, the quantitative parameters of the thrombin generation test and a number of coagulogram indicators pointed to hypocoagulation in the intraoperative and early postoperative periods. Conclusion: The comparative analysis of local tests characterizing the state of hemostasis and indicators of integral methods demonstrated the advantages of the latter in assessing thrombotic risks during implantation of vascular grafts. Local tests are not sufficient to assess the dynamics of the coagulation process in real time and are not always sensitive to hypercoagulation. The use of integral methods will help to fill these gaps, make a timely diagnosis of hypercoagulability and minimize the risks associated with the implantation of vascular grafts in future.

Comparative Analysis of the Hemostasiological Profile in Sheep and Patients with Cardiovascular Pathology as the Basis for Predicting Thrombotic Risks During Preclinical Tests of Vascular Prostheses.

The aim of the investigation was to study the details of hemostasiological profile in sheep and patients with coronary heart disease (CHD) and to find the possibility of predicting thrombotic risks during preclinical tests of vascular prostheses on a large laboratory animal model. Materials and Methods: The functional activity of platelets was measured in platelet-rich plasma with inductors: ADP, epinephrine, collagen. Prothrombin activity, international normalized ratio, activated partial thromboplastin time (APTT), thrombin time, fibrinogen concentration, antithrombin III and protein C activity, fibrinolysis were determined in blood plasma. Changes in clot formation and viscoelastic properties of clots were assessed using thromboelastography. Results: Significant differences were found in the hemostasiological profile of sheep and CHD patients. Sheep platelets had increased response to ADP induction and practically no response to epinephrine induction; collagen-induced aggregation was comparable in the study groups. Coagulation hemostasis of sheep was characterized by increased activity of the prothrombin complex, shortened thrombin time, while APTT and fibrinogen values remained comparable. At the same time, sheep exhibited a significant decrease in the activity of anticoagulant and fibrinolytic systems as compared to CHD patients. When assessing dynamic changes in clot formation, it was observed that initiation phase was faster in animals, while clot density exceeded that in patients. Conclusion: The hemostasiological profile of sheep is characterized by the increased speed of thrombus formation, greater strength of the formed clot, and lower lysis ability as compared to CHD patients. The revealed details of the hemostasiological profile of sheep can be potential targets for therapy with antithrombotic drugs that minimize thrombotic risks in preclinical testing of vascular prostheses.

The relationship of the epicardial fat and adipo-fibrokines in myocardial infarction.

Analysis of the relationship between the epicardial fat with adipokine and system ST2/IL-33 in-hospital period, and also with the extent of fibrosis of the atrial myocardium through the year after myocardial infarction in patients with visceral obesity. Examined 88 patients with myocardial infarction (MI). Visceral obesity (VO) is established by computed tomography. In fact the presence VO the patients divided into two groups. Determined the concentration of leptin, adiponectin, stimulating growth factor (ST-2) and interlekin-33 (IL-33) in serum on 1st, 12-day in-hospital period and 1 year after MI. Thickness epicardial adipose tissue (EAT) and the percentage of cardiovirus of the myocardium was measured by the method MRI, respectively, on the 12th day of hospitalization and a year after MI. The control group consisted of 30 people. Statistical analysis of data was performed using nonparametric tests. Patients with MI is associated with an increase in the thickness of EAT, imbalance of adipokines with increased leptin, decreased adiponectin in early in-hospital period and development of cardiovirus. Higher values of IL-33 and ЅT2 in the early in-hospital period MI patients with no accompanied by a lower prevalence of cardiovirus in the post-hospital period. The thickness of epicardial fat is directly dependent on the prevalence of myocardial fibrosis, the concentrations of IL-33 and in inverse proportion to the concentration of ЅT2. The degree of cardiovirus is in inverse proportion to the concentration of IL-33 and directly dependent on the concentration of ST2. The increase in EAT closely linked to the development of fibrosis of the atrial myocardium after year. The thickness of EAT more patients MI, which is most pronounced imbalance of adipokines. The metabolic activity of EAT correlated with increased IL-33 and ST2 decrease.

[Adiponectin gene expression in local fat depots in patients with coronary heart disease depending on the degree of coronary lesion].

AIM: To determine the dependence of adiponectin gene expression by subcutaneous, epicardial and perivascular adipocytes on the degree of coronary lesion in coronary heart disease. MATERIALS AND METHODS: 84 patients with coronary artery disease were examined. Of these, 39 people showed a moderate degree of atherosclerotic lesion of the coronary bed (less than or equal to 22 points) on the SYNTAX Score scale, 20 severe (2231 points), and 25 extremely severe (more than 32 points). Upon admission to the hospital, all patients underwent an echocardiographic study (Echocardiography, Acuson, Germany) with the calculation of the ejection fraction (EF) of the left ventricle (LV) to assess its systolic function. During a planned surgical intervention (coronary bypass surgery, CABG), adipocytes of subcutaneous, epicardial (EAT) and perivascular adipose tissue (PVAT) were taken. Adiponectin gene expression was evaluated by polymerase chain reaction (real-time PCR) using TaqMan probes. Statistical analysis was performed using Statistica 9.0. RESULTS: The maximum level of adiponectin expression was detected in adipocytes of PVAT, and the minimum EAT. With an increase in the degree of atherosclerotic lesion of the coronary bed, the expression of the adiponectin gene in adipocytes of local depots significantly decreases r=-0.82; p=0.023. Moreover, the low level of gene expression in EAT correlated with a decrease in LV EF by r=0.73; p=0.03. In adipocytes of subcutaneous and especially PVAT, gene expression was the highest in patients with a moderate degree of coronary lesion. CONCLUSIONS: Low adiponectin gene expression in EAT is associated with an increase in the degree of atherosclerotic lesion of the coronary bed and a decrease in LV EF.