On an analogue of Schwarz's reflection principle

We consider the Bergman space on the complex plane. We prove an analogue of Schwarz's reflection principle for unbounded quasidisks

Safety of Non-Vitamin K Oral Anticoagulants in Elderly Patients with Atrial Fibrillation

Aim. To study the safety of non-vitamin K oral anticoagulants (NOAC) in patients with atrial fibrillation (AF) over 75 years old.Material and methods. The observation study included patients ≥75 years of age with confirmed AF, receiving dabigatran in a reduced dosage, apixaban or rivaroxaban in full or reduced dosage. Previous experience of NOAC treatment from the very beginning of therapy, if a patient was ≥75 years old, or from the point a patient reached 75 years was considered; episodes of NOAK change, as well as hemorrhagic and ischemic events associated with taking an anticoagulant, were recorded. Patient groups were comparable in risk score by CHA2DS2-VASc and HAS-BLED scales.Results. Patients with AF (n=102; 39 men and 63 women; an average age 79.4Ѓ}4.1 years) were included: 32 patients were in dabigatran group, 34 patients – in apixaban group and 36 patients – in rivaroxaban group. 19 clinically significant bleedings were recorded, 10 occurred in patients taking dabigatran and 9 in those taking rivaroxaban. No hemorrhagic events in patients treated with apixaban were observed. Hematuria (31.6%), large subcutaneous hematomas (26.3%) and intensive nasal bleedings (26.3%) were the most frequent events. No ischemic cardioembolic stroke was recorded.Conclusions. In elderly patients, all NOAC (dabigatran, rivaroxaban and apixaban) demonstrated good safety profile without major bleeding within a 1.5-year follow-up period

Features of Thromboembolic and Hemorrhagic Complications in Planned Surgical Interventions in Patients with Atrial Fibrillation

Aim. To study the frequency and characteristics of the development of thromboembolic and hemorrhagic complications in patients with atrial fibrillation (AF) during planned surgical interventions.Material and methods. Preoperative examination and postoperative observation of 214 patients with AF (139 men and 75 women) who received anticoagulant therapy (ACT) and underwent planned surgery was carried out. The consistency of the used perioperative ACT regimens when performing interventions with current international recommendations was analyzed.Results. Complications developed in 33 patients (15.4%) from the total sample of 214 patients: in 14 (6.5%) thromboembolism, in 19 (8.9%) hemorrhagic complications. Analysis of the complication frequency in various types of surgical interventions showed that the frequency of thromboembolism during heart and vascular operations was 9.8% (4 cases), with interventions for malignant tumors – 7 (6.2%), while performing general surgical abdominal tumors operations – 3 (5.0%). The frequency of bleeding was maximum during operations for cancer 18.6%, this value was significantly higher compared with the frequency of these complications when performing general surgical abdominal operations – 3 cases (5.0%), and during interventions on the heart and vascular vessels bleedings were not observed. The total frequency of complications was also maximal when performing interventions for malignant tumors – 24.8%. This value was significantly higher than in the groups of patients who underwent general surgical abdominal operations – 10.0%, and interventions on the heart and vessels – 9.8%. Analysis of the frequency of compliance with the recommendations of the European Society of Cardiology in terms of ACT usage in patients with AF in the perioperative period and the structure of errors in choosing the ACT regimen showed that among the examined patients the recommendations were followed only in 102 (47.7%), while the frequency of non-recommended regimens use reached 52.3% (112 patients). The most frequently incorrectly used scheme was “bridge therapy” with the possibility of canceling oral anticoagulants in 107 (50.0%) patients.Conclusion. A significantly higher frequency of complications was found in patients, whose management did not follow the recommendations for perioperative ACT

«Fragility» as a predictor of bleedings in elderly patients with atrial fibrillation taking direct oral anticoagulants

The purpose of the study is to assess the contribution of senile asthenia level to hemorrhagic complications quantity in elderly patients with atrial fibrillation (AF) taking direct oral anticoagulants (DOAC).Material and methods. Elderly patients >75 y.o. with AF taking dabigatran, apixaban or rivaroxaban in full or reduced dosages and without special features of bleeding (such as double and triple antithrombotic therapy) were included in the study. If a patient was under anticoagulants before the study (but not earlier than one became 75 y.o.), this experience was also analyzed. All bleedings during the first 18 months of anticoagulating were taken in mind. Patients in different DOAC groups were comparable in age and concomitant pathology. The «fragility» index was evaluated at the stage of inclusion in the study; an adapted Rockwood scale was used.Results and discussion. 102 patients with AF >75 y.o. taking dabigatran, apixaban or rivaroxaban in dosages corresponding to the instructions were included in the study. During the analyzed period, 19 small clinically significant hemorrhagic events that did not require hospitalization or cancellation of DOAC were recorded. Patients with and without bleeding in anamnesis were significantly differed only by «fragility» index score (р = 0,001). The differences between concomitant pathology level which are mentioned in scale, is also not statistically significant. The average age of patients with and without bleeding anamnesis was not also significantly different (p = 0.12). In the future, it is advisable to continue the study using several scales for assessing the severity of the «fragility» index. Thus, it is advisable to calculate the «fragility» index in patients >75 years of age with AF taking DOAC

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

New Possibilities in Quantitative Assessment of Albuminuria in Patients with Atrial Fibrillation and Chronic Kidney Disease

Aim. To evaluate the relationship between albumin to creatinine ratio (ACR) in a single and 24-hours urine spots and chronic kidney disease (CKD) progression pace in patients with atrial fibrillation, CKD and diabetes mellitus.Material and methods. 60 patients with atrial fibrillation (AF) and CKD were enrolled, study duration was 15 months. The patients were divided into two groups depending on the presence of DM. Total number of ACR tests was 170, dynamics of CKD progression was estimated with CKD-EPI formula for first visit and 15th month’s follow-up.Results. The median score of CHA2DS2VASс scale was 4 [3;5]. The risk of hemorrhagic complications in both groups was low (median score 1 [1;1]. There is a strong statistically significant correlation between ACR in a single and 24-hours urine spots (p<0.001). No significant changes in kidney function within 15 months were found (GFR 53 [46;59] ml/min/1.73 m2 vs 50.5 [45.63] ml/min/1.73 m2 for patients with diabetes mellitus [DM] [p=0.94] and GFR 52.5 [46.58] ml/min/1.73 m2 vs 50 [44.58] ml/min/1.73 m2 for patients without DM [p=0.711]). When comparing the renal function of patients with and without DM after 15 months statistically significant differences were also not found (p = 0.510).Conclusion. In respect that assessment of single sample ACR is much more practical and reliable, this method might replace traditional 24-hours urine assessment in future. However, due to the small sample size and the presence of wide discrepancies in individual cases, which can be associated with preanalytical errors in urine collection, large randomized clinical trials are needed to confirm the obtained data

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

Breast cancer incidence following low-dose rate environmental exposure: Techa River Cohort, 1956–2004

In the 1950s, the Mayak nuclear weapons facility in Russia discharged liquid radioactive wastes into the Techa River causing exposure of riverside residents to protracted low-to-moderate doses of radiation. Almost 10 000 women received estimated doses to the stomach of up to 0.47 Gray (Gy) (mean dose=0.04 Gy) from external γ-exposure and 137Cs incorporation. We have been following this population for cancer incidence and mortality and as in the general Russian population, we found a significant temporal trend of breast cancer incidence. A significant linear radiation dose–response relationship was observed (P=0.01) with an estimated excess relative risk per Gray (ERR/Gy) of 5.00 (95% confidence interval (CI), 0.80, 12.76). We estimated that approximately 12% of the 109 observed cases could be attributed to radiation

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