Peculiarities of Hemostasis and Proteomics in Patients With Acute Myocardial Infarction and Healthy Volunteers After SARS-CоV-2 Infection.

AIM: To identify the features of plasma, platelet hemostasis, and proteomic composition of the blood plasma in patients with acute myocardial infarction (AMI) and healthy volunteers after COVID-19. MATERIAL AND METHODS: The study included patients with AMI who have recently had COVID-19 (AMI-post-COVID, n=56) and patients with AMI who have not recently had COVID-19 (AMI-control, n=141). Healthy volunteers constituted the control groups and were also divided into control-post-COVID (n=32) and control-control (n=71) groups. Previous SARS-CoV-2 infection was determined by anti-N IgG in the blood serum, the level of which persists for 6-10 months after the disease. Hemostasis was evaluated by thromboelastometry (on whole blood), thrombodynamics (on platelet-poor plasma), fibrinolysis, impedance aggregometry, and proteomic analysis. RESULTS: The AMI-post-COVID and AMI-control groups had higher values of thrombus growth rate, size and density based on the data of thromboelastometry and thrombodynamics, as well as increased concentrations of the complement system components, proteins regulating the state of the endothelium, and a number of acute-phase and procoagulant proteins compared to the control groups. Furthermore, in the AMI-post-COVID group, compared to the AMI-control group, the thrombus density was lower, and its lysis rates were higher when measured by the thrombodynamics method on platelet-poor plasma, while the platelet aggregation induced by ADP and thrombin was higher. Also, in the control-post-COVID group, compared to the control-control group, the thrombus formation rate was lower, whereas, in contrast, the thrombus size as measured by the thrombodynamics method and the platelet aggregation induced by arachidonic acid and thrombin were higher. In addition, in the AMI-post-COVID group, compared to the AMI-control group, the concentrations of proteins involved in inflammation and hemostasis were lower. CONCLUSION: Patients with AMI who have recently had COVID-19 are characterized by a less pronounced activation of the immune response compared to patients with AMI who have not had COVID-19. This may be due to long-term chronic inflammation and depletion of components of the immune activation system after SARS-CoV-2 infection. Long-term activation of the hemostasis system in both patients with AMI and healthy volunteers after COVID-19 is primarily due to the platelet component of hemostasis.

The state of platelet and plasma hemostasis as a predictor of coronary blood flow in patients with acute myocardial infarction.

Aim      To study the relationship of the platelet function and plasma homeostasis with the blood flow in the infarct-related artery (IRA) and with the course of acute myocardial infarction (AMI).Material and methods  This study included 93 patients with AMI (75 patients with ST-elevation AMI and 18 patients without ST segment elevation). 63 patients had TIMI 0-1 blood flow in the IRA and 30 patients had TIMI 2-3. Rotational thromboelastometry, impedance aggregometry, the endothelium-dependent vasodilation (EDVD) test, and the thrombodynamics test were performed for all patients. The primary clinical endpoint included the totality of in-hospital complications of AMI, and the secondary endpoint included the totality of out-of-hospital complications of AMI. Major bleedings (BARC 3-5) and minor bleedings (BARC 1-2) were evaluated separately.Results Patients with IRA TIMI 0-1 flow were characterized by a shorter blood clotting time (BCT), larger thrombus size and density, more intense platelet aggregation induced by arachidonic acid and ADP, and lower values of the EDVD test. It was found that the parameters of platelet aggregation induced by arachidonic acid (AUC Asa) in combination with BCT allowed assessment of the severity of IRA blood flow disorder (sensitivity 76 %, specificity 71 %) in patients with AMI, regardless of the presence of ST segment elevation on the ECG. In addition, the incidence of the primary endpoint was greater in patients with IRA TIMI 0-1 flow (41.3% and 16.7%, respectively; p=0.015). In patients with TIMI 2-3 flow in the long-term period of the disease, the incidence of minor bleedings was significantly higher (8.5% and 30.4 %, respectively; p=0.045).Conclusion      Compared to patients with preserved blood flow, patients with AMI and IRA TIMI 0-1 flow are characterized by endothelial dysfunction and more intense processes of thrombogenesis and platelet aggregation. It has been shown for the first time that the combination of two simple criteria for assessing hemostasis (AUC Asa; BCT) allows assessment of the degree of IRA blood flow disorder in patients with AMI.

[Peculiarities of hemostasis in patients with COVID-19].

AIM: Analysis of the dynamics of different stages of clot formation and its lysis in patients with different COVID-19 severity. MATERIALS AND METHODS: We prospectively included 58 patients with COVID-19 (39 patients with moderate disease severity and 18 patients with severe disease) and 47 healthy volunteers as a control group. All participants underwent the assessment of flow-mediated dilation (FMD) of brachial artery, impedance aggregometry, rotational thromboelastometry and thrombodynamics. Von Willebrand factor antigen (vWF:Ag) quantification was also performed in patients with COVID-19. Measurements were repeated on the 3rd and 9th day of hospitalization. RESULTS: Compared to the control group, patients with COVID-19 showed reduced values of platelet aggregation and greater values of the clot growth rate, as well as its size and density. On the first day of hospitalization, we found no differences in the activity of plasma hemostasis and endogenous fibrinolysis between subgroups of patients. With the progression of the disease, the growth rate and size of the clot were higher in the severe subgroup, even despite higher doses of anticoagulants in this subgroup. An increase in platelet aggregation was noted during the progression of the disease, especially in the severe subgroup. There were no differences in the results of the FMD test by subgroups of patients. The vWF:Ag level was significantly higher in the severe subgroup. CONCLUSION: Thus, plasma hemostasis followed by secondary platelet activation correlates with the severity of COVID-19. Patients with moderate to severe coronavirus infection have predominantly local rather than generalized endothelial dysfunction.

Pecularities of Candida yeast identification by mass spectrometric analysis (MALDI-ToF MS).

To carry the comparative analysis of sample preparation methods for the most effective identification of Candida yeast by mass spectrometric analysis. 265 strains of yeast and yeast-like fungi isolated from the sputum of patients with pneumonia were investigated. The selected strains were identified by conventional methods (cultural, morphological, tinctorial, enzymatic properties) and MALDI-ToF MS using the Autoflex speed III Bruker Daltonics mass spectrometer (Germany) and Flex Control software. To evaluate the effectiveness of fungi species determinination, the comparative analysis of sample preparation was performed using 4 methods: direct application to the target, an extended direct application method, protein extraction using ethanol/formic acid or trifluoroacetic acid. The accelerated scheme of identification of fungi by the culture method does not provide clear and unambiguous results. When using mass spectrometric analysis, the reliability of the results depended on the sample preparation. A comparative study of the effectiveness of fungi species determination by various methods of the sample preparation of 50 clinical isolates was carried out. It was revealed that the extraction of cells using TFC acid does not lead to the appearance of the recordable protein spectra. The use of direct and extended direct application methods made it possible to establish the species only in 32-44% of the strains. The most effective method of sample preparation was the method using formic acid and ethanol, which allowed us to determine the species affiliation in 100% of the studied fungi (Score 2.0). Depending on the yeast species, a high statistical indicator (Score≥2.3) was registered for 42-100% of samples. The results of present study show that the use of MALDI-ToF MS is the most reliable and informative method of Candida spp.identification.

Evaluation of the Applicability of the Comparatory Method for Species Diagnosis of Unionidae (Bivalvia) by Genetic Analysis.

Five genetically distant groups of mussels possessing high intragroup homogeneity were identified among 65 specimens of 14 East European Unionidae "comparatory species" by genetic analysis of nuclear and mitochondrial markers. By shell morphology other than the shape of the convex contour of the shell, the identified groups correspond to five "taxonomic species" according to Zhadin's classification. The use of the comparatory method for Unionidae species identification is unjustified.

[Assessment of the use of various cardiac pacing modes for selection of antiarrhythmic therapy for prevention of recurrent attacks of atrial fibrillation and flutter]. / Otsenka ispol'zovaniia razlichnykh rezhimov kardiostimuliatsii dlia opredeleniia protivoretsidivnoi antiaritmicheskoi terapii paroksizmov mertsaniia i trepetaniia predserdii

AIM: To determine optimal mode of transesophageal pacing for selection of appropriate antiarrhythmic therapy for prevention of attacks of atrial fibrillation and flutter in patients with ischemic heart disease. MATERIAL AND METHODS: Two hundred eighteen patients with ischemic heart disease and attacks of atrial fibrillation or flutter. Selection of antiarrhythmic drugs was carried out with the use of competitive, rapid, salvos of ultra rapid, and slowly accelerating ultra rapid modes of pacing. Results. Most effective and reproducible method for induction of attacks of atrial flutter and fibrillation was slowly accelerating ultra rapid mode of pacing. Average duration of positive clinical effect of preventive antiarrhythmic therapy selected basing on the results of this mode in patients with ischemic heart disease was 3.1-/+0.3 years. Unfavorable prognostic sign decreasing preventive effect of antiarrhythmic therapy was left atrial dilatation. CONCLUSION: Slowly accelerating mode of transesophageal pacing was most effective tool for selection of antiarrhythmic therapy aimed at prevention of attacks of atrial fibrillation and flutter in patients with ischemic heart disease.