Concerns Rise Over Thrombotic Complications in Patients With COVID-19

Although the coronavirus disease 2019 (COVID-19) is primarily viewed as a pulmonary disease, clinicians are becoming increasingly concerned about evidence that it could also be a thromboembolic disease.

In addition to acute respiratory distress syndrome and its effects on patients with respiratory failure, some evidence now suggests that microvascular thrombotic processes may play a role in patients’ respiratory failure.

A report from the National Institute for Public Health of the Netherlands found a potential link between mortality, D-dimer values, and a prothrombotic syndrome among patients with COVID-19. They noted that although there are no publications on the incidence of venous thromboembolism, the authors noted that there are case reports on thromboembolic disease, stroke, and myocarditis.

A single-center retrospective cohort study in China investigated disseminated intravascular coagulation (DIC) and found that 71% of 21 non-survivors were classified as having overt DIC any time during follow-up, compared with just 0.6% of 162 survivors of the COVID-19 infection.

Complications with the coagulation system have also been noted, as is common in a variety of different viruses. Vascular endothelial damage in both small- and mid-sized pulmonary vessels has been noted in previous outbreaks of severe acute respiratory syndrome-coronavirus (SARS-CoV). Based on these observations, the authors said similar complications are likely to be found in patients with COVID-19.

In light of these observations among patients with COVID-19, the authors recommended initiation of several diagnostic and preventive actions.

Antithrombotic therapy has been found to lower mortality rates in some studies. Most notably, a single-center retrospective cohort study of 449 consecutive patients diagnosed with severe COVID-19 in China found that prophylactic doses of heparins might be associated with improved survival in patients with evidence of sepsis-induced coagulopathy (SIC).

Of the 449 patients, 99 received heparin for 7 days or longer. The drug was associated with lower 28-day mortality among 97 patients with a SIC score of 4 or greater, but not among the patients with a score less than 4.

Chest CT scans have also been proposed in order to enable standardized reporting. According to the authors, the typical CT pattern of a patient with COVID-19 pneumonia in Rome, Italy, was characterized by the consistent presence of peripheral ground glass opacities associated with multi-lobar and posterior involvement, bilateral distribution, and subsegmental vessel enlargement.

A recent retrospective study of 1008 patients in which 25 underwent CT pulmonary angiography found acute pulmonary embolism (PE) in 10 patients (40%), which were mainly located in subsegmental vessels.

The authors concluded with several basic recommendations for the diagnostic and therapeutic management of patients with suspected or confirmed COVID-19:

• Prophylactic-dose low-molecular-weight heparin should be initiated in all patients admitted to the hospital with suspected COVID-19, regardless of risk scores.
• A baseline non-contrast chest CT should be considered in all patients with suspected COVID-19 who have an indication for hospital admission.
• CT pulmonary angiography should be considered in patients with suspected COVID-19 as well as a high clinical suspicion for PE if the D-dimer level is elevated.
• In patients with COVID-19 who are admitted to the hospital, routine D-dimer testing on admission and during the hospital stay should be considered.

REFERENCE

Ourkerk M, Buller H, Kuijpers D, van Es N, et al. Diagnosis, Prevention, and Treatment of Thromboembolic Complications in COVID-19: Report of the National Institute for Public Health of the Netherlands. Radiology; April 23, 2020. https://pubs.rsna.org/doi/10.1148/radiol.2020201629. Accessed May 6, 2020.