dcyphr | Prevalence of venous thromboembolism in patients with severe novel coronavirus pneumonia


The abnormal blood coagulation function of severe COVID-19 patients is well known. But the prevalence of venous thromboembolism (VTE) is not. This study aims to determine the prevalence of VTE in severe COVID-19 patients. An ultrasound was used to determine if 81 severe patients had VTE. 25% of the patients had VTE, and 40% of the patients with VTE passed away. Age, lymphocytes, activated partial thromboplastin time (APTT), and D-dimer were all differing factors between VTE and non-VTE patients.


Many studies on SARS-CoV-2 have shown coagulation dysfunction in severe patients. This coagulation is associated with a poor outcome. VTE in severe COVID-19 patients and its effects are not well understood. This study identifies VTE in patients and the difference between VTE and non-VTE patients. 81 patients with severe COVID-19 cases were included in this study. The patients had a clinical examination, blood work, chest CT, lower limb venous doppler ultrasound, and an RT-PCR test for COVID-19. They were tested for prothrombin time, activated partial thromboplastin time, thrombin time, international normalized ratio, fibrinogen, and D-dimer. These are known as conventional coagulation tests.

Results and Discussion

The average age of the patients was 59.9 years. 41% of the patients had another chronic disease and 43% of the patients were smokers. 25% of the patients developed VTE. The VTE patients were older on average than the non-VTE patients. The VTE patients also had lower lymphocyte counts, longer activated partial thromboplastin time (APTT), and higher D-dimer. The D-dimer was still higher than the normal range for both VTE and non-VTE patients.

Other studies have also shown SARS-CoV-2 infection leads to low lymphocyte count. T cells seemed to be the most affected because they were half of the low limit. Abnormal expression of T cell mRNA can cause VTE, and older patients are more likely to have this complication.SARS-CoV-2 can also lead to sepsis and the release of proinflammatory cytokines. Inflammatory cytokines can activate blood coagulation therefore promoting VTE. Sepsis can also cause a spread in clots into vasculature  which occurred in deceased patients at a rate of 71.4%. This shows that abnormal blood coagulation and thrombosis do not have a favorable outcome in severe COVID-19 patients.

    High D-dimer levels are linked to high coagulation and hyperfibrinolysis. After the patients had anticoagulant medication. The D-dimer level decreased slowly. D-dimer can therefore predict thrombosis and monitor how effective the anticoagulant medication is.

Though this study was small and the clinical outcomes of all of the patients are yet to be discovered, this study will assist in the prevention, diagnosis, and treatment of VTE.