As we progress through the COVID-19 pandemic, research into the pathogenesis of the SARS-CoV-2 virus has revealed a complex range of symptoms associated with the disease. Recently, evidence has been mounting that a significant proportion of patients with severe COVID-19 have coagulation abnormalities. Studies from the Netherlands and France have even suggested that blood clots may arise in as many as 20-30% of critically ill COVID-19 patients (Klok et al., 2020; Poissy et al., 2020).
So why would an infection of the respiratory tract cause blood clots? Could anticoagulants increase COVID-19 survival?
Although patients with COVID-19 primarily have a respiratory tract infection, new research is beginning to reveal that patients with severe COVID-19 may have coagulation abnormalities that can cause an increased risk of death (Tang et al, 2020a).
Within the complex interplay of factors present in coagulation, the formation of D-dimer proteins after the fibrinolysis of blood clots has proven to be a powerful predictor of mortality in patients hospitalised with COVID-19 (Zhang et al, 2020).
Research has found blood clots in small vessels of people with severe COVID-19 (Magro et al., 2020) and a recent observational study found that systemic anticoagulation is associated with improved outcomes among patients hospitalised with COVID-19 and on mechanical ventilation (Paranjpe et al., 2020).
While scientists are continually working to find new vaccines, improve testing and understand the pathogenesis of the disease, research is being carried out to build a clearer picture of how clotting occurs in people with COVID-19.
Currently, the utility of anticoagulation therapy and the appropriate level of dosing is still a matter of hot debate. Various novel anticoagulants developed over the years for a wide variety of targets, yet little research has so far been carried out to determine the best anticoagulants for treating COVID-19 associated blood clotting.