Cancer is one of the most significant risk factors for the development of venous thromboembolic complications, and also increases the risk of arterial thrombosis mainly in the coronary and cerebrovascular arteries. The article aimed to examine the direct toxic effects on vascular endothelium demonstrated by specific classes of chemotherapeutic drugs, tumor procoagulant effect, inhibition of endogenous fibrinolysis, and increased platelet aggregation among the pathogenetic mechanisms of these complications. The article is presented in two parts. The first part examines the traits of the hemostasis state in cancer, some pathogenetic mechanisms of arterial and venous thrombosis, and the management of cancer patients with the arterial thrombosis. The second part provides a review of the literature on the prevention and treatment of cancer-associated venous thromboembolic complications.

The article presents the experience in management of occlusive deep vein thrombosis with enoxaparin sodium in outpatient settings. The study included two groups of patients: the patients of the first group received unfractionated heparin for 10-14 days, followed by the treatment of patients with vitamin K antagonists (warfarin), and the patients of the second group also received enoxaparin sodium for 1 month with subsequent treatment with vitamin K antagonists.
The study showed that the use of enoxaparin for the period of 1 month in combination with vitamin K antagonists significantly improved the results of treatment of these patients. It was also found that the use of enoxaparin sodium increased neither the risk of hemorrhagic complications nor the risk of thrombocytopenia.

After percutaneous coronary intervention, patients receive double antiplatelet therapy for several months, which includes acetylsalicylic acid and a P2Y12 receptor inhibitor. In most cases, managing the patients with the atrial fibrillation requires adding an anticoagulant drug to the antiplatelet therapy — triple antithrombotic therapy. The rejection of triple therapy in favour of the administration of an anticoagulant and only one antiaggregant is a prospective line of reducing the risk of bleeding in these patients. The number of studies evaluating the effectiveness and safety of such therapy remains limited, and the guidelines for anticoagulant therapy are largely based on the studies of only "stable" patients with atrial fibrillation and on the results of registers, i.e. data of “real-life” clinical practice. The RE-DUAL PCI study showed that the administration of dabigatran in combination with the P2Y12 receptor inhibitor in patients with atrial fibrillation after percutaneous coronary intervention is much safer and no less effective than the classical triple therapy. A special feature of the study was the evaluation of the effectiveness and safety of two doses of dabigatran, each of which was approved for stroke prevention. This provides clinicians with additional options for treating patients with atrial fibrillation after percutaneous coronary intervention.

Despite the decline in cardiovascular mortality rate in recent decades due to the widespread use of antihypertensive, hypocholesterolemic and antiplatelet drugs, various manifestations of ischemic heart disease (IHD) retain one-third of the mortality pattern in individuals older than 35 years [1–3]. In regions with a developed health system, cardiovascular mortality is gradually declining. However, death from various manifestations of IHD remains the leading cause of death among adults regardless of income level [4].

Platelet P2Y12-receptor inhibitors are ranked 2nd in terms of administration frequency among antiplatelet agents (after acetylsalicylic acid). Administration of such drugs is mandatory in conditions characterized by increased activation of platelets, which, above all, include acute coronary syndrome and percutaneous coronary interventions. The use of clopidogrel, the most famous and commonly used today representative of P2Y12 receptor inhibitors, does not always result in reducing a risk of thrombotic complications.
The new generation representatives of the of P2Y12 receptor inhibitors (prasugrel, ticagrelor, cangrelor) showed their advantage over clopidogrel in the large-scale studies and are expected to improve the treatment situation not only in patients with acute coronary syndrome and after percutaneous coronary interventions, but also in other high-risk groups.

The article considers the issues of pathogenesis, diagnostics and intensive therapy of acute DIC-syndrome with underlying dysfunction of anticoagulant system. It also shows the role of early laboratory diagnostics of decreased antithrombin III activity for optimization of intensive therapy of acute DIC syndrome. The possibility of using antithrombin III concentrate has been demonstrated from the perspective of evidence-based medicine and real clinical practice.

Use of antiplatelet therapy in the world indicates real difference in individual drug effect between patients, including the effect on prognosis. Problems of personification of individual approach, concerning antiplatelet therapy, are discussed.

The article presents a clinical discussion of the patient with recurrent venous thromboembolic complications. It also provides recommendations on modern principles of diagnostics, choice of medical tactics in patients with this pathology. Much attention is paid to the issues of anticoagulant treatment, which inadequacy or failure results in the development of severe, difficultly treatable complications.

Impairments in haemostatic system function may result in the clinical manifestations in the form of haemorrhagic and/or thrombotic episodes and their combinations. Such cases are widespread in clinical practice, and a physician across specialties may face them. The creation of a laboratory examination program at the initial stage and in the follow-up of a patient depends on the clinical situation and working hypothesis, on the involvement of various mechanisms of the haemostasis system. Screening tests are the basis of the initial examination algorithms for the patient. Additional tests are added based on the initial examination results, clinical picture and medical history data. It is necessary to understand the essence of the performed examinations, their characteristics and the areas of responsibility of each in order to effectively use modern laboratory diagnostic capabilities. The most important clinical decisions can be made on the basis of the lab examination results — from establishing diagnosis to identifying the risks of recurrent thrombotic or haemorrhagic events and creating an appropriate secondary prevention program and choice of therapies, lifestyle changes, pregnancy planning and contraceptive methods.

Renal artery aneurysm (RAA) is a rare disease that is found in most cases by chance.
According to early studies data, detection of RAA in autopsy was accounted for 0.01% to 0.09%. In patients with RAA located intraparenchymatically or in the area of __the kidneys, the endovascular intervention cannot be carried out, and open resection of the aneurysm can be extremely difficult due to poor visualization, which makes the surgeons to perform the nephrectomy in most cases. We present a clinical example of the extracorporeal resection of the renal artery aneurysm located in the kidney gates.

Atrial fibrillation (AF) is the most common indication for the long-term oral anticoagulation therapy. For several decades, vitamin K antagonists have been the mainstay of routine clinical practice.
A prospective 10-year follow-up of patients with atrial fibrillation receiving warfarin therapy showed that the incidence of all cerebral circulation disorders was 2.59 per 100 patient-years. The warfarin therapy contributed to the prevailing of non-fatal events among the cerebral circulation disorders which occurred during the therapy. The incidence of fatal ischemic strokes was 0.91 per 100 patient-years over the 10-year follow-up study.
If the duration of a patient within the target therapeutic range (TTR) was <70%, it increased the relative risk of ischemic cerebrovascular disorders by 2.77 times (95% CI 1.367--5.633) compared with patients with a mean value of TTR ≥ 70%.
The study demonstrated that 86.5% of patients with the mean TTR values ≥ 70% had no ischemic cerebrovascular disorders for 10 years. A separate analysis of patients with high thromboembolic risk (who had 4 or more points on the CHA2DS2-VASc) showed that achieving a TTR ≥ 70% resulted in 70.7% patients who had no stroke for 10 years.
The stepwise discriminant analysis revealed that the initial cognitive function decline, history of stroke and TTR <70% were predictors of developing ischemic cerebrovascular disorders (strokes and transient ischemic attacks) in patients receiving warfarin.

Platelets play an important role in initiating atherothrombosis, i.e. the formation of blood clots inside a blood vessel at areas of atherosclerotic vascular injury. The functional (prothrombotic) activity of platelets significantly varies both in healthy individuals and in patients with cardiovascular diseases. The increased platelet production and turnover may be one of the reasons for promoting platelet activity. Stimulating thrombocytopoiesis results in large and reticular (with an increased amount of RNA) "young" platelets in the bloodstream. These platelets contain more adhesive receptors, more secretory granules and have an increased aggregation capacity. The review provides data indicating that large and reticular platelets are not only markers, but also predictors of atherothrombotic events, and primarily of acute coronary syndrome. An increase in such platelet count in patients receiving antiplatelet drugs is associated with a decrease in effectiveness of their antiplatelet action. It is assumed that the appearance of large and reticular platelets in the blood of patients with atherosclerosis and atherothrombosis may be a consequence of an increase in the thrombopoietic activity of megakaryocytes in these pathological conditions.