The Incidence of Thrombosis and Heparin-Dependent Thrombocytopenia in Patients With COVID-19 and Pneumonia With a Course of the Disease Complicated by Acute Kidney Injury
Authors: Teplova Natalia Vadimov , Evsikov Evgeny , Bairova Kermen Ivanovna , Dzheksembekov Aldar Gabitovich , Gagikovich Vardanjan Argishti 
Published: May 2024

_RELEVANCE._ Thrombosis is one of the most dangerous complications of COVID-19, not only at the peak of the disease, but also in the long-term period. During the pandemic, issues of medical prevention of thrombotic complications have been repeatedly reviewed, clarified and supplemented, but the only correct tactics for their diagnosis, prevention and treatment do not yet exist.

_PURPOSE OF THE STUDY._ Determination of the frequency and nature of the development of heparin-dependent thrombocytopenia, accompanied by venous and arterial thrombosis in severe patients with COVID-19 and pneumonia, with a course of the disease complicated by acute kidney injury (AKI), including death, assessment of the effectiveness and safety of their antithrombotic therapy.

_MATERIAL AND METHODS._ Inpatient treatment and diagnostic data 216 patients with COVID-19 with viral pneumonia and signs of acute kidney injury (AKI) according to KDIGO 2012 criteria. Group 1. Deceased patients with severe Covid-19 and pneumonia, with unreliable signs of AKI, 75 (men 19, women 56), ratio 1: 2.9. Age from 29 to 87 years. Mechanical ventilation in 56 (74.7%). Group 2. Died patients with covid-19 and pneumonia with reliable signs of AKI, 77 (men 34, women 43), ratio 1: 1.3. Age from 41 to 88 years. Mechanical ventilation in 53 (70.7%) Group 3. Recovered patients with AKI or CKD, 64 (41 men, 23 women, ratio 1:0.56, age from 43 to 89 years). Mechanical ventilation in 1 (1.6%). Hemostasis study. Activated partial thromboplastin time according to the modified method of plasma recalcification reaction according to Baluda V.P. et al. (1980). The level of fibrinogen in blood plasma studied by the ethanol method according to Breen F., Tullis J. (1982). Determination of the concentration of D-dimer in the blood by microlatex agglutination with photometric registration of the reaction (immunoturbidimetry).

_RESULTS._ In deceased inpatients with Covid-19 and pneumonia, a high, up to 46-56%, incidence of arterial and venous thrombosis of various localizations was revealed. Thrombotic risk was largely associated with increased levels of D-dimer and the duration of its increase in the blood of patients. Thrombocytopenia was diagnosed in 47-58% of patients and was a significant risk factor for the development of deaths. In cases where thrombocytopenia was detected in patients below 20 thousand cells per μl, its nature was assessed on the 4Ts scale to identify heparin-dependent thrombocytopenia syndrome. In 92-97% of patients, heparins were prescribed, including fractionated (low molecular weight) ones such as enoxaparin, nadroparin, dalteparin and fundaparinux. Some cases of a combination of thrombosis and thrombocytopenia (about 2.3%) were due to the nature of the drug therapy and the development of confirmed heparin-associated thrombocytopenia syndrome.

_CONCLUSION._ The data obtained indicate the possibility of the development of heparin-dependent thrombocytopenia syndrome and the high significance of thrombotic mechanisms with the participation of D-dimer in the pathogenesis and outcomes of the disease in groups of deceased patients with covid-19 and pneumonia, complicated by acute kidney injury and the predominant importance of vascular damage in the activation of thrombotic cascade.