Extended therapy and secondary prevention of venous thromboembolic complications

Venous thromboembolic complications (VTEC) are acute and time-limited diseases. However, the recurrence rate after a first episode of VTEC is high and potentially life-threatening. Developed deep vein thrombosis (DVT) and thromboembolism of pulmonary artery (TEPA) are inevitably associated with use of anticoagulant therapy (ACT). A peculiarity of the modern clinical management of patients with VTEC is determination of duration of ACT. Aim. To study possibilities of prolonged anticoagulation therapy and secondary prevention of venous thromboembolic complications taking into consideration modern variants of drug therapy, on the basis of literature data. Search for literature was conducted in Medline and Elibrary databases including materials published in 2020. Randomized clinical and observational studies and meta-analyses, concerning prolonged therapy and secondary prevention of VTEC with vitamin K antagonists (VKA), peroral anticoagulants (POAC), sulodexide and aspirin, were analyzed. As it is evidenced by patho-physiological and epidemiological data, risk of VTEC recurrence in most patients is not resolved after the first 6 months of treatment with anticoagulants. In such situations it is reasonable to prolong anticoagulation for an indefinite period of time. However, sometimes a limiting factor for prolonged therapy with anticoagulants is bleedings caused by prolonged anticoagulation, sometimes leading to lethal outcome. Therefore, duration of treatment in the long-term period after an acute episode may rest on the balance between the risk of development of recurrence of venous thrombosis and bleeding, evaluated with the help of scales. The main achievement of recent years regarding prolonged therapy and secondary prevention of VTEC, are POAC, which in fact are new and alternative drugs that permitted the emergence of serious evidential basis in the range of means for treatment of this category of patients, sulodexide drug has appeared characterized by the minimal rate of development of large and clinically significant bleedings. Conclusion. The emergence of serious evidential basis for POAC with improved safety profiles, different pharmacokinetic profiles and dosage regimens, including sulodexide that has been actively used in recent years for secondary prevention of VTEC, will permit clinicians to differentially approach treatment of different clinical variants of venous thrombosis, to improve the results of therapy taking into account evaluation of the individual risk and comorbid diseases, and compliance of patients.