Atrial Fibrillation: a Marker or Risk Factor for Stroke

Atrial fibrillation (AF) is strongly associated with stroke risk, but an association by itself does not necessarily imply causation. The question remains whether AF is a risk factor for stroke and whether treatment that reduces the severity of AF will also reduce the burden of stroke. On the other hand, it is possible that AF is a risk marker associated with atrial insufficiency, in which structural and electrical atrial remodeling coexist, leading  to the clinical manifestations of AF and the risk of stroke simultaneously. Atrial fibrillation and stroke are inextricably linked to the classic Virchow pathophysiology, which explains thromboembolism as blood stasis in a fibrillating left atrium. This concept has been reinforced by the proven efficacy of oral anticoagulants for the prevention of stroke in AF. However, a number of observations showing that the presence of AF is neither necessary nor sufficient for stroke cast doubt on the causal role of AF in vascular brain injury. The growing recognition of the role of atrial cardiomyopathy and the atrial substrate in the development of stroke associated with AF, as well as stroke without AF, has led to a rethinking of the pathogenetic model of cardioembolic stroke. A number of recent studies have shown that AF is a direct cause of stroke. Studies in which cardiac implantable devices have been used to collect data on pre-stroke AF do not appear to show a direct time relationship. The presence of AF is neither necessary nor sufficient for stroke, which casts doubt on the causal role of AF in cerebrovascular injury. Known risk factors for stroke in the presence of AF are also recognized risk factors for ischemic stroke, regardless of the presence of AF. The risk of stroke in patients with AF in the absence of risk factors differs little from that in patients without AF. This work is devoted to an attempt to answer the question whether AF is a marker or a risk factor for ischemic stroke

Left Ventricular Thrombosis: Current Perspective and Use of Direct Oral Anticoagulants

Left ventricular thrombus (LVT) is a serious risk factor for systemic embolism development. Despite the evident danger of this condition, current guidelines describe management of patients with this potentially fatal complication very briefly. LVT can complicate myocardial infarction where its incidence is around 10%, as well as various forms of cardiomyopathies and novel coronavirus infection. According to clinical guidelines vitamin K antagonists (VKAs) should be used as treatment of choice for thrombus resolution. However, experts point out that this therapy lacks necessary evidential base and bears certain difficulties because of pharmacokinetic and pharmacodynamical properties of VKAs. These drawbacks are absent in direct oral anticoagulants (DOACs), the possibility of using which in LVT is being actively studied. As for now, published results of 3 randomised clinical trials have demonstrated similar safety and efficacy profiles of DOACs and VKAs. Similarly, the majority of retrospective cohort studies did not observe significant differences between two groups, where some of them have shown superiority of DOACs especially in terms of earlier thrombus resolution. Nevertheless, some studies have found DOACs ineffective and even potentially unsafe regarding systemic embolism. Existing data does not allow to form an unambiguous conclusion about the equivalence of DOACs and VKAs for LVT resolution. Large randomised clinical trials are needed to determine efficacy and safety of such treatment in these patients

«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

Thrombodynamics Test in Assessing the Risk of Thrombus Formation in Patients with Atrial Fibrillation Taking Direct Oral Anticoagulants

Aim. To evaluate thrombus characteristics in patients with atrial fibrillation (AF) taking different direct oral anticoagulants (DOACs) using Thrombodynamics test.Materials and methods. Thrombodynamics test was performed in 100 patients with paroxysmal and permanent forms of AF taking different DOACs, dose choice was done in accordance with the instructions for drugs use. For analysis samples of fresh citrated platelet-free plasma were taken just before regular DOACs dose intake (trough concentration). Statistical data processing was carried out using R software packages.Results. All patients had no history of thrombosis or bleeding before inclusion in this study. All parameters of Thrombodynamics test taken at residual concentration of DOACs were in general within reference values, that is in the area of normal coagulation: spatial clot growth rate (V) – 26.56 (25.0; 29.2) μm/min, the time to the start of clot growth (Tlag) – 1.05 (0.85; 1.27) min, initial spatial clot growth rate (Vi) – 44.3±7.7 μm/min, stationary spatial clot growth rate (Vst) – 26.5 (24.9; 28.4) μm/min, clot size (CS) – 999.7 (912.9; 1084.7) μm, clot density (D) – 22883.1±3199.9 arb. units. D was appeared to be higher in women [22947.7 (21477.5; 22947.7) vs men [22124.8 (19722.8; 22124.8), p=0.035] and Tlag was significantly higher in patients with chronic heart failure [1.2 (1.0; 1.2) vs 1.0 (0.8; 1.0), p=0.008]. A correlation was found between level of creatinine and Tlag parameter, glomerular filtration rate (GFR) and clot density. With an increase in the level of creatinine in the blood and a decrease in GFR, respectively, there was an increase in Tlag parameter (p-value 0.038); with an increase in GFR, clot density decrease (p-value 0.005).Conclusion. All parameters of Thrombodynamics test on residual concentration of DOACs were within reference values that indicated optimal anticoagulant effect of all DOACs. The obtained data of normal coagulation at the residual concentration of the anticoagulant are consistent with the previously obtained data on the safety and effectiveness of DOACs using other methods. Further studies with clinical end points are needed to assess the clinical value of this method

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

ЭЛЕКТРОЭНЦЕФАЛОГРАФИЧЕСКИЕ КОРРЕЛЯТЫ ОПТИМАЛЬНОГО ФУНКЦИОНАЛЬНОГО СОСТОЯНИЯ ГОЛОВНОГО МОЗГА СПОРТСМЕНА В СТРЕЛКОВОМ СПОРТЕ

The goal of the research was a detailed characterization of the pre-shot EEG alpha activity of marksmen. It was found out that the amplitude of the spectrum of alpha activity is dependent upon the level of the sportsmen. It is discussed that the pre-short alpha is not similar with alpha rhythm in its classical definition.Цель работы – детальный анализ альфа-диапазона электроэнцефалограммы стрелков различного уровня. Показана зависимость выраженности альфа-диапазона электроэнцефалограммы перед выстрелом от уровня мастерства спортсмена. Рассматривается сдвиг доминирующей частоты аль-фа-диапазона в период, предшествующий выстрелу, в более высокочастотную область относительно фонового альфа-ритма. Обсуждаются физиологические механизмы выявленных отличий между стрелками и испытуемыми контрольной группы при помощи тренингов на основе биоуправления

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

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701