Officially announced by the World Health Organization (WHO) in March 2020, the coronavirus disease 2019 (COVID-19) pandemic is terrifying with the unimaginable rate of spreading and the large number of deaths. More than 171 million COVID-19 cases including more than 3,6 million deaths have been confirmed worldwide since the start of the pandemic. The high incidence of venous thromboembolic events and non-ARDS (acute respiratory distress syndrome) associated death of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, despite prophylactic antithrombotic therapy, may indicate the need for a more intensified personalized regime of preventive measures. Respiratory viruses such as influenza A H1N1, SARS-CoV, MERS-CoV and SARS-CoV-2 are known for their affinity for lung tissue and the ability to lead to viral pneumonia and acute respiratory distress syndrome (ARDS). The analyzed data bring up to the hypothesis that microvascular thrombosis, rather than decreased lung compliance, provides oxygenation impairment in COVID-19 patients. The accumulated experience in the management of patients with SARS-CoV-2 indicates that the pathophysiology of systemic microthrombosis associated with COVID-19 may differ from that in sepsis-induced disseminated intravascular coagulation (DIC). In contrast to sepsis-induced coagulopathy consumption of platelets, clotting factors, fibrinogen, and bleeding are rare in patients with severe SARS-CoV-2, suggesting that DIC is not a common complication of COVID-19. The development of micro- and macrovascular thrombosis of the venous and arterial bed in patients with SARS-CoV-2 makes it possible to consider COVID-19 as a systemic “thromboinflammatory” syndrome. According to the international analytical studies, the proportion of thrombosis and thromboembolic complications ranges from 0.9% to 6.5 in patients with a moderate COVID-19, and from 8% to 69% in patients treated in intensive care unit, the proportion of acute arterial obstruction in SARS-CoV-2 patients ranges 0.39% to 11.1%. The team of authors carried out a retrospective analysis of the medical records of 7607 patients hospitalized in 2020 in the infectious disease departments of the 4th city clinical hospital named after N.E. Savchenko. The proportion of patients with pulmonary embolism (PE) in the final diagnosis was 2.1% (n=163), the proportion of patients with deep vein thrombosis (DVT) was 0.9% (n=68), in the structure of patients with DVT the complication of PE was 58.8% (n=40). The variation in the data of national and foreign studies may apparently be related to different diagnostic tactics in verifying the diagnosis of VTE and DVT: the use of duplex ultrasound vascular examination and/or computed tomographic angiography (CTA) of the lungs as screening techniques, the inclusion of different clinical points (symptomatic and/or asymptomatic VTE) by authors in publications, the lack of uniform approaches to thromboprophylaxis, and population differences in the patient samples. There is an urgent need for more in-depth studies of the pathogenesis and molecular basis of thrombosis in patients with COVID-19 to establish the prognostic value of changes in the hemostasis system associated with SARS-CoV-2. Considering unknown long-term results in COVID-19 convalescents, many studies signaling the presence of disabling consequences and the need for subsequent full medical and non-medical rehabilitation, the search for new biomarkers, such as of coagulation, fibrinolysis, activation of endothelium, that are associated with the course, early outcomes and delayed complications in patients with coronavirus infection (SARS-CoV-2) remains relevant.
Coronavirus: A Disease of the Haemoglobin? Suggested Therapeutic Approaches
