ИССЛЕДОВАНИЕ СТРУКТУРЫ И ФАЗОВОГО СОСТАВАПОРОШКОВЫХ АЛЮМОФОСФОРИСТЫХ ЛИГАТУР

There were developed powder aluminium-phosphorus master alloys for modification of hypereutectic silumins. There was se-lected the best performance processing of powder mixes in the high-energy planetary mill that ensured minimum losses of feed stock and microstructure with uniform and disperse distribution of the proeutectoid constituents’ particles in aluminium matrix. By means of X-ray diffraction study was investigated phase composition of obtained master alloys. There was demonstrated high efficiency of the modification of hypereutectic silumins Al–17wt.%Si by alloying of phosphorus (0,008 wt.%) obtained master alloys.Разработаны порошковые алюмофосфористые лигатуры для модифицирования заэвтектических силуминов. Выбраны оптимальные режимы обработки порошковых смесей в высокоэнергетической планетарной мельнице, обеспечивающие минимальные потери исходного материала и микроструктуру с однородным и дисперсным распределением в алюминиевой матрице частиц избыточных фаз. Методом микрорентгеноспектрального анализа исследован фазовый состав полученных лигатур. Показана высокая эффективность модифицирования заэвтектического силумина Al–17мас.%Si введением фосфора (0,008 мас.%) полученными лигатурами

Risk of Venous Thromboembolic Complications in Patients with Atrial Fibrillation: a Systematic Review and Meta-analysis

Aim: The aim of this meta-analysis and systematic review was to evaluate the possible connection between AF and VTE.Material and methods. Atrial fibrillation (AF) and atrial flutter (AFL) contribute to intra-atrial blood stasis which leads to thrombus formation with its embolization. There is some evidence that AF can be a risk factor for deep vein thrombosis (DVT) and pulmonary embolism (PE). The following databases were searched: PubMed (MEDLINE), EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials. The time frame for conducting a systematic literature search ranged from January 1, 1990 to November 1, 2021. The diagnosis of atrial fibrillation had to be confirmed by using ECG. The diagnosis of VTE could be made with Doppler imaging, ventilation/perfusion scan, CT angiography, venography, angiography or autopsy. Only the three studies with 102192 patients meeting the requirement were included in the meta-analysis.Results. The prevalence of DVT and PE were assessed using incidence rate ratios (IRR) method of the inverse variance random effects model and its 95% confidence interval (CI). The significant association between atrial fibrillation and pulmonary embolism was found (IRR, 4.18 95% Cl 1.958.98). Also there is obvious association between DVT and AF (IRR, 2.97 95% Cl 2.18-4.03).Conclusion. It can be concluded that the increased risk of developing VTE is associatedwith concomitant AF

Возможности оценки системы гемостаза при фибрилляции предсердий и тромбозе ушка левого предсердия

Thromboembolic syndrome, the frequency of which is 8–15%, is the main danger for a patient with atrial fibrillation (AF). The left atrial appendage is the most common source of thromboembolia in atrial fibrillation. The frequency of detection of left atrial appendage thrombus in AF is 15.2% in the absence of anticoagulant therapy and 1–8% in patients using this group of drugs. The reason for the formation of thrombi in this localization during anticoagulant therapy today it is not reliably known. This article describes a clinical case of a 67-year-old patient with persistent AF and left atrial appendage thrombosis, who was hospitalized to determine further management strategies. A left atrial appendage thrombus lasted for a year despite continuous anticoagulant therapy with various oral anticoagulants at doses consistent with clinical guidelines due to the patient's absolute refusal to take warfarin, vitamin K antagonist. In addition, this article discusses the use of Thrombodynamics, a new global coagulation test, in patients with AF, which revealed a plasma hypercoagulable state with underlying persistent thrombosis in this patient on continuous oral anticoagulant treatment. The Thrombodynamics test is a promising procedure for assessing the coagulation system state and may be promising as a method for measuring the effectiveness of any oral anticoagulant. However, it is impossible to draw any definite conclusions on the basis of single observations; large clinical studies with the potential of long-term case follow-up of patients are needed.Основную опасность при фибрилляции предсердий (ФП) для пациента представляет тромбоэмболический синдром, частота которого составляет 8–15%. Наиболее частым источником тромбоэмболии при фибрилляции предсердий является ушко левого предсердия. Частота выявления тромба в полости ушка левого предсердия при ФП составляет 15,2% при отсутствии антикоагулянтной терапии и 1–8% у пациентов на фоне приема препаратов этой группы. Причина формирования тромбов данной локализации на фоне антикоагулянтной терапии к настоящему времени достоверно неизвестна. В данной статье описывается клиническое наблюдение пациентки 67 лет с персистирующей формой ФП и тромбозом ушка левого предсердия, которая была госпитализирована для определения дальнейшей тактики ведения. Тромб в ушке левого предсердия сохранялся в течение года, несмотря на проводимую антикоагулянтную терапию различными пероральными антикоагулянтами в дозах, соответствующих клиническим рекомендациям ввиду абсолютного отказа пациентки от приема антагониста витамина К варфарина. Кроме того, в данной статье обсуждается применение нового глобального теста «Тромбодинамика» у пациентов с ФП, который продемонстрировал у данной пациентки состояние гиперкоагуляции плазмы крови на фоне продолжающейся антикоагулянтной терапии и персистирующего тромбоза. Тест «Тромбодинамика» представляет собой многообещающую методику для оценки состояния свертывающей системы крови и может быть перспективным в качестве метода измерения эффективности любого перорального антикоагулянта. Однако на основании единичных наблюдений невозможно делать какие-либо определенные выводы, необходимы крупные клинические исследования с возможностью длительного динамического наблюдения за пациентами

Effectiveness of heparin versus 0.9% saline solution in maintaining the permeability of central venous catheters: a systematic review

Abstract OBJECTIVE Determining which is the most effective solution (heparin flush compared to 0.9% saline flush) for reducing the risk of occlusions in central venous catheters (CVC) in adults. METHOD The systematic review followed the principles proposed by the Cochrane Handbook; critical analysis, extraction and synthesis of data were performed by two independent researchers; statistical analysis was performed using the RevMan program 5.2.8. RESULTS Eight randomized controlled trials and one cohort study were included and the results of the meta-analysis showed no difference (RR=0.68, 95% CI=0.41-1.10; p=0.12). Analysis by subgroups showed that there was no difference in fully deployed CVC (RR=1.09, CI 95%=0.53-2.22;p=0.82); Multi-Lumen CVC showed beneficial effects in the heparin group (RR=0.53, CI 95%=0.29-0.95; p=0.03); in Double-Lumen CVC for hemodialysis (RR=1.18, CI 95%=0.08-17.82;p=0.90) and Peripherally inserted CVC (RR=0.14, CI 95%=0.01-2.60; p=0.19) also showed no difference. CONCLUSION Saline solution is sufficient for maintaining patency of the central venous catheter, preventing the risks associated with heparin administration

Modern therapeutic potential of super-selective β¹-adrenoblocker nebivolol

Beta-adrenoblockers, included in any cardiovascular disease treatment standard, became a key part of clinical practice only in late XX century. Nebivolol is a highly selective beta-1 -adrenoiblocker, modulating endothelial NO release and subsequent physiological vasodilatation. Nebivolol has multiple clinical indications, including coronary heart disease, arterial hypertension, and chronic heart failure. Due to its super-selectivity it can also be beneficial in patients with diabetes mellitus, chronic obstructive pulmonary disease, and erectile dysfunction

Metformin in metabolic syndrome treatment

Aim. To compare the influence of standard and complex (including metformin) antihypertensive therapy on 24- hour blood pressure monitoring (BPM), biochemical and hormonal parameters in patients with metabolic syndrome (MS). Material and Methods. The study included 54 patients with MS: 34 males and 20 females aged 30-61, without manifested Type 2 diabetes mellitus (DM). Group A (28 MS patients) received antihypertensive drugs only – verapamil, if necessary combined with ACE inhibitors and diuretics. Group B (25 MS patients) was additionally administered metformin. At baseline and after 8-week therapy, 24-hour BPM was performed; basal levels of insulin, C-reactive protein (CRP), cholesterol, triglycerides (TG), high-density lipoproteins (HDL), and uric acid were measured. Results. In Group A, there was no significant dynamics in lipid and carbohydrate metabolism parameters. In Group B, basal levels of CRP (p<0.05), TG (p<0.1) had decreased, and HDL concentration has increased (p<0.01). Conclusion. In MS patients without DM, adding minimal therapeutic doses of metformin to standard antihypertensive treatment significantly improved lipid and carbohydrate metabolism parameters

Anticoagulant therapy in patients with atrial fibrillation and concomitant chronic kidney disease: the results of a prospective study

In recent years, both Russian and foreign authors have published many papers on anticoagulant therapy for atrial fibrillation (AF). The largest are devoted to the study of direct oral anticoagulants (DOACs), which have appeared in this field since 2009, and their comparison with vitamin K antagonists (VKAs) in terms of efficacy, safety and other important characteristics. There are far fewer studies on DOACs and their comparison with VKAs and with each other in patients with AF and reduced kidney function. Most of them are retrospective. Meanwhile, the prevalence of chronic kidney disease (CKD) in the population is very high, and doctors are faced with a problem of selecting anticoagulant therapy for these patients.Purpose. To assess the effect of VKAs and DOACs on renal function in real clinical practice in patients with AF depending on the stage of CKD.Materials and methods. A prospective single-centre non-randomized non-interventional observational study in parallel groups was conducted. The study included 92 patients with AF and CKD of 1-4 stages (S1-S4). The comparison group consisted of 35 patients with AF without concomitant CKD. The patients’ age ranged from 44 to 94 years (mean age was 72.2 ± 8.5 years). Patients of both groups received anticoagulant therapy with VKA (warfarin) or one of the registered in the Russian Federation DOACs (dabigatran, rivaroxaban, apixaban). During the observation (median was 10 months), follow-up visits were every 3 months. On visits we conducted the evaluation of effectiveness (strokes / TIA and thromboembolic complications) and safety (major and minor hemorrhagic events) of anticoagulant therapy, as well as the dynamics of kidney function (CC by Cockroft-Gault, GFR by CKD-EPI).Results. The main results are devoted to patients with AF and concomitant CKD. Significant dynamics of the kidney function depending on the anticoagulant taken (VKA or representatives of the DOACs class) were not identified. There were not any thromboembolic complications and major bleedings during the observation period. Statistically significant more minor bleedings on any dose of rivaroxaban in comparison with other anticoagulants were identified.Conclusions. In patients with AF and CKD, there was no significant effect of one or another anticoagulant on the kidney function, which is probably related to the concomitant nephroprotective therapy obtained in a large percentage of cases (ACE inhibitors / ARA, calcium antagonists, statins). Therapy with DOACs and warfarin in patients with AF and CKD for an average of 10 months of followup was effective and safe. In case of AF and CKD combination, the use of dabigatran or apixaban seems to be more preferable in relation to minor bleedings, the use of which less often leads to the development of hemorrhagic events

PREDICTORS OF THE RISK OF HEMORRHAGIC EVENTS IN PATIENTS WITH ATRIAL FIBRILLATION RECEIVING LONGTERM THERAPY WITH DIRECT ORAL ANTICOAGULANTS

Aim. To study the initial disorders in the coagulation system, as factors influencing the development of bleeding during anticoagulant therapy with direct oral anticoagulants (DOAC).Material and methods. 117 patients receiving DOAC (direct thrombin inhibitors – dabigatran, and Xa factor inhibitors – rivaroxaban and apixaban) were included into the cohort study in parallel groups. In addition to evaluate the efficacy and safety of therapy, an extensive analysis of the blood hemostasis system was performed in patients before the start of anticoagulant therapy.Results. No thromboembolic events and major bleedings were registered in patients receiving DOAC during 24 month observation. No significant correlations were observed between minor bleeding frequency in both groups (16.33% in dabigatran group and 22.39% in Xa factor inhibitors group) and troponin I and hemoglobin levels, as well as HAS-BLED and ATRIA risk scores. Among patients receiving dabigatran initial decrease in von Willebrand factor plasma level (p=0.02) and increase in fibrinogen blood concentration (p=0.02) were predictors of minor bleedings. These predictors of bleeding events were not found in Xa inhibitor groups.Conclusions. DOAC in patients with atrial fibrillation showed their efficacy and safety without any differences between classes of direct thrombin inhibitors and Xa factor inhibitors. Among the possible predictors of spontaneous minor hemorrhagic events on the dabigatran therapy, a reduced level of von Willebrand factor and elevated fibrinogen level may be considered when choosing a dose of the drug. Markers of hemorrhagic complications development were not determined for the Xa factor inhibitors. Limitation of this study was the absence of randomization, that is why the results should be interpreted with caution

SAFETY OF DIRECT ORAL ANTICOAGULANTS IN PATIENTS WITH ATRIAL FIBRILLATION: A TWO-YEAR COHORT STUDY

Real-life clinical application of anticoagulant drugs is currently one of the most promising trends in cardiology. With relation to initial prescription of anticoagulants, the updated 2016  guidelines  on the management  of patients with atrial fibrillation (AF) highlight direct oral anticoagulants (DOAC) rather than vitamin K antagonists, but, unfortunately, they are not clear about whether different DOAC have the same clinical effect of there is a significant difference.Material and methods. We conducted a comparative analysis of the safety of DOAC in patients with non-valvular AF and attempted to identify the potential predictors of hemorrhagic events in order to assess  the predictive value of bleeding risk scores. For this purpose, we observed 117 patients with non-valvular AF who received DOAC to prevent TEC for 2 years (24 months).Results. Over the entire period of follow-up, no major bleeding or thromboembolic complications were recorded, supporting the good efficacy and safety profile of DOAC. We analysed the prognostic value of various scores and found that HAS-BLED had the highest predictive value in the group of patients treated with the direct thrombin inhibitor (dabigatran). Treatment with factor Xa inhibitors (rivaroxaban and apixaban) did not demonstrate a similar trend.Conclusion. Over the 2-year follow-up of 117 patients treated with DOAC, we were able to show that this group of drugs in patients with non-valvular AF is effective and safe given that adequate doses in accordance with the instructions are administered; this is true for both direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban and apixaban). HAS-BLED was prognostically more accurate when the direct thrombin inhibitor dabigatran was administered