Semin Thromb Hemost 2020; 46(07): 772-776
DOI: 10.1055/s-0040-1710337
Commentary

Coronavirus Disease 2019, Prothrombotic Factors, and Venous Thromboembolism

Sam Schulman
1  Department of Medicine, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
2  Department of Obstetrics and Gynecology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
› Author Affiliations

Coronavirus disease 2019 (COVID-19) is causing devastating morbidity and mortality worldwide. Several studies have shown that the severely ill patients have high or very high D-dimer values, and a hypercoagulable state has been described with, in some cases, development of disseminated intravascular coagulation (DIC). A few reports have indicated that there seems to be a higher incidence of venous thromboembolism than expected in otherwise severely ill patients. In this article, we will discuss the prothrombotic changes observed and to what extent they are specific for COVID-19. The incidence of thromboembolic events will be compared with those reported in sepsis and severe influenza A H1N1. The emphasis is on venous events, which have been the most frequently reported events. Finally, the intensity of pharmacological prophylaxis against venous thromboembolism will be discussed.

The pandemic of COVID-19 is affecting almost every country in the world, with the number of cases tested and found infected exceeding two million, with an overall mortality of approximately 7% at the time of writing.[1] There are preliminary reports from China on venous thromboembolism based on a relatively small number of patients.[2] [3] Subsequently, European physicians have reported a higher incidence of thromboembolic events, mainly venous, in patients with COVID-19 pneumonia in the intensive care unit (ICU).[4] Another manifestation of hypercoagulability is DIC, which was not reported in other than the occasional case in the largest published cohorts.[5] [6] [7] On the other hand, abnormalities in the coagulation tests, meeting previously defined criteria for DIC, were observed during the terminal days in 71% of nonsurvivors in another cohort from Wuhan, China.[8]

These preliminary findings generate several questions, some which are as follows:

  • What are the indicators of hypercoagulability in COVID-19 infection?

  • Is the hypercoagulability specific for COVID-19 infection?

  • Does the hypercoagulability result in a higher incidence of thromboembolism than in other patients with severe infection in the ICU?

  • If so, is it justified to use higher than standard doses of pharmacological prophylaxis against thromboembolism in these patients?

It should be recognized that the data on this infection are rapidly emerging and that information obtained from countries in Europe or North America might differ from those in China due to variations in ethnic susceptibility, environmental conditions (e.g., pollution and health care resources availability), diagnostic routines, and prophylaxis regimens. Therefore, any assumptions or conclusions drawn in this article can be proven wrong after a short time.



Publication History

Publication Date:
11 May 2020 (online)

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