Oncological disease increases the risk of developing arterial thrombosis mainly in the coronary and cerebrovascular beds. Among the pathogenetic mechanisms of this complication the authors consider the direct toxic effect on the endothelium produced by some groups of chemotherapeutic drugs, the procoagulant effect of the tumor, inhibition of endogenous fibrinolysis and increased platelet aggregation. Activation of the inflammation caused by increased synthesis of inflammatory mediators and adhesion molecules is also relevant, as well as vasospastic and direct damaging effects of radiation therapy on the endothelium. Patients with ACS against the background of the ongoing oncological process, on the one hand, are at a high risk for thrombotic complications, while, on the other hand, they have limitations for antiplatelet therapy due to thrombocytopenia. Therefore, the decision on the possibility, composition and duration of antiplatelet therapy in such patients should be taken by cardiologists jointly with oncologists and chemotherapists. The article has two parts. The first examines the specific hemo-stasis in cancer, some mechanisms of the pathogenesis of arterial and venous thrombosis, as well as treatment of cancer patients who developed arterial thrombosis. The second part provides a review of the literature on the prevention and treatment of venous thromboembolic complications associated with cancer.

Fondaparinux is a parenteral selective factor-Xa inhibitor. The drug is successfully used in the treatment of acute coronary syndrome, and is characterized by the ideal profile of effectiveness and safety. In the case of ACS without ST-segment elevation, fondaparinux is the drug of choice regardless of the treatment strategy - early invasive or conservative. In the case of PCI, an anticoagulant with anti-IIa activity (either UFH or bivalirudin) should be administered immediately before the procedure. In patients with ACS with ST-segment elevation, fondaparinux is used as an anticoagulant accompaniment of thrombolysis (primarily, with streptokinase) or in patients not receiving reperfusion therapy. In the case of elective primary PCI in these patients, it is more appropriate to use UFH. For the treatment of ACS, fondaparinux is used at a dose of 2.5 mg/day and administered within 8 days, up until discharge (if it happens earlier) or a successful PCI. The greatest benefits from the use of fondaparin- ux should be expected in patients with a high risk for bleeding, including in patients with moderate renal failure with a decrease in creatinine clearance to 30-60 ml/min.

The review discusses the results of using oral anticoagulants to improve the prognosis of patients after exacerbation of coronary artery disease. Based on a review of the available randomized clinical trials, the authors conclude that rivaroxaban at a dose of 2.5 mg twice daily has the best efficacy/safety ratio. Administration of rivaroxaban at the mentioned dose within 1 year after the development of acute coronary syndrome helps to reduce cardiovascular and total mortality and the risk of stent thrombosis.

The current clinical guidelines for the treatment of patients with acute coronary syndrome (ACS) claim that simultaneous use of two drugs that inhibit platelet activity is mandatory for most patients. This approach known as dual antiplatelet therapy (DAT), in view of the similarity of the mechanisms of the disease development, should be used in both ACS with ST elevation (STE-ACS) and in ACS without ST elevation (non-STE-ACS). In both cases, DAT should combine acetylsalicylic acid (ASA) with a P2Y12 receptor antagonist (ticagrelor, prasugrel or clopidogrel). For Russia, where prasugrel is not registered, the most preferable DAT is the combination of ASA with ticagrelor which has outperformed clopidogrel in terms of efficacy in the PLATO trial. [1]

Prevention of stroke remains one of the most pressing healthcare issues. Acetylsalicylic acid (ASA) is the only antithrombotic drug used for primary and secondary prevention of atherothrombotic stroke. A serious and challenging limitation to extensive antithrombotic therapy in ischemic stroke is the risk of hemorrhagic complications, primarily intracranial hemorrhages. In primary prevention of stroke in individuals without clinical manifestations of atherosclerosis, it is especially important to correlate the perceived benefit and the possible risk posed from the administration of ASA. The combination of ASA with other antiplatelet drugs (dipyridamole, clopidogrel) could additionally benefit some patients after stroke or transient ischemic attack.

Apixaban is the only NOA the administration of which is associated with a reduction in the incidence of both stroke and major bleeding. Therefore, apixaban is the drug of choice in patients with non-valvular AF, including elderly patients, patients with a high risk of bleeding complications, as well as in patients with impaired renal function. In clinical practice, the efficacy and safety of apixaban are not inferior to those obtained in the ARISTOTLE trial. Apixaban is safe when used during cardioversion and catheter ablation. The results of pre-clinical studies provide implications for further investigation into the possibility of administration of apixaban in patients with «valvular» AF.

The article presents a comparative evaluation of the current clinical angiographic scales in the risk stratification for patients with stable coronary artery disease undergoing elective percutaneous coronary interventions. The article discusses the prospects for improving the prognostic value of scales by adding two laboratory markers reflecting the degree of coagulation cascade activation and the adequacy of antiplatelet therapy — D-dimer and residual platelet reactivity to adenosine diphosphate.

The review article highlights the views reflected in the recent clinical guidelines related to high-intensity statin treatment and non statin cholesterol lowering drugs in patients with very high cardiovascular risk after myocardial infarction and the purpose of therapy. The article tells about the approaches to controlling lipidogramic parameters after high-intensity statin therapy was prescribed and to the prescription of PCSK9 inhibitors (Alirocumab) after an acute coronary event. The report was compiled on the basis of the available materials from the national and foreign databases (e-Library, Library’s MEDLINE/PubMed database).

For patients with atrial fibrillation, long-term oral anticoagulant therapy reduces the risk of ischemic stroke and systemic embolism, while increasing the risk of hemorrhagic complications. To assess the safety of therapy, along with major bleeding, minor and clinically relevant bleeding also should be taken into account. Minor, especially recurrent hemorrhages usually do not provide a reason for discontinuing anticoagulant therapy. The described follow-up demonstrated the absence of major hemorrhage in the patient with recurrent minor hemorrhagic complications against a background of 15-year course of anticoagulant therapy (including 9-year course of dabigatran treatment).

A trial fibrillation occurs in 5 to 8% of patients who underwent percutaneous coronary intervention (PCI) with stenting. It is known that dual antiplatelet therapy (a combination of P2Y12 receptor inhibitor and acetylsalicylic acid) significantly reduces the risk of developing stent thrombosis in comparison with vitamin K antagonists; however, anticoagulants are significantly more effective in reducing the risk of ischemic stroke in patients with atrial fibrillation (AF). When opting for a long-term triple antithrombotic therapy, the risk of hemorrhagic complications increases dramatically, while choosing less intensive treatment results in an increased risk of ischemic complications, primarily, ischemic stroke and stent thrombosis. The current recommendations come down to the prescription of all of the three components of antithrombotic therapy. However, this approach leads to a significant increase in the frequency of hemorrhagic complications. The purpose of recent randomized trials was to compare and evaluate the efficacy and safety of different regimens with antithrombotic drugs in combination with rivaroxaban in patients with AF who underwent PCI.

The article describes current views on the role of antiplatelet therapy in the secondary prevention of cardiovascular diseases in patients after non-cardioembolic ischemic stroke or transient ischemic attack (TIA). Based on the findings of evidence-based medicine, an analytical description of all platelet antiaggregants that have been clinically tested worldwide is presented. The benefits and shortcomings of each agent both in mono- and combination therapy are demonstrated. The novel ideas about rationality of the combination antiplatelet therapy with clopidogrel and acetylsalicylic acid in the first 24 hours lasting up to 90 days in patients with small ischemic stroke or TIA are highlighted. The effectiveness and safety of new platelet antiaggregants are analyzed. The key principles that guide the choice of antiplatelet agents in patients after ischemic non-car-dioembolic stroke are outlined.

A ptamers are a new class of oligonucleotide compounds capable of specific binding to various molecular targets and inhibiting their activity. Aptamers are selected from a library of randomly syn-thesized oligonucleotides (from 20 to 60 nucleotides long) based on their ability to bind to the target molecule. In the future, such primary aptamers can be chemically modified to optimize their structure and increase stability. Aptamers are considered to be chemical (oligonucleotide) analogues of monoclonal antibodies: their specificity is similar to that of antibodies, and they have high affinity to their targets. Aptamers are widely used to create pharmacological medicines. As pharmacological substances, they have a number of benefits over antibodies and other protein molecules. Aptamers are practically non-immunogenic, chemically synthesized without the use of biological producers, and their antidotes can easily be created using complementary sequences. The review highlights reports devoted to the development of new anticoagulant aptamer-based medications. The most detailed studies, both preclinical and clinical (various phases of clinical trials), were performed in relation to the study of aptamers against vWF, factor IX and thrombin.

Despite the long-term clinical experience, bleeding remains the greatest danger for patients taking vitamin K antagonists. Moreover, even the presence of risk factors for hemorrhagic complications in a patient should not be the only reason for cancelling anticoagulant therapy. The challenge in assessing the frequency of hemorrhage is primarily explained by different approaches to hemorrhage classification. For patients receiving long-term anticoagulant therapy, along with fatal and life threatening hemorrhages, minor and clinically significant small hemorrhages should be taken into account to assess the safety of treatment. The 15-year prospective follow-up of patients receiving warfarin found that the frequency of all hemorrhagic complications was 8.66/100 patient-years, major hemorrhage — 2.98/100 patient-years, and clinically significant hemorrhage — 2.62/100 patient-years. According to the results of the discriminant analysis, the predictors for the development of major and clinically significant hemorrhagic complications in patients receiving long-term therapy with warfarin are administration of proton pump inhibitors, labile INR during therapy, recurrent minor hemorrhage in history and amiodarone therapy. The 15-year prospective follow-up of patients receiving warfarin demonstrated that minor hemorrhagic complications account for one third of all bleedings and are not associated with the subsequent development of clinically significant and major bleeding in patients. The prospective follow-up also found an increase in the frequency of hemorrhagic complications if one or two antiplatelet agents were added to warfarin therapy. The incidence of major and minor clinically significant hemorrhagic complications during triple antithrombotic therapy was 24/100 patient-years, which was higher than in the warfarin monotherapy subgroups and in the case of combining warfarin with an antiaggregant (4.4 and 8.47%, respectively). The localization of bleeding was analyzed to reveal that in triple antithrombotic therapy the greatest number of bleedings occurred in the upper or lower gastrointestinal tract. The relative risk was calculated to confirm that triple antithrombotic therapy significantly increased the risk of gastrointestinal bleeding by 3.02 times.