Blood coagulation abnormalities play an important role in the pathophysiology of COVID-19. However, the specific details of hyper-coagulation and anticoagulant treatment require further investigations.

The objective was to study the indicators of two global tests for the status of the hemostasis system assessment in patients with COVID-19 at the time of admission to the clinic (before the start of anticoagulant therapy) and in patients receiving heparin during treatment in the clinic.

MATERIAL AND METHODS

Global thrombodynamics (TD) and thromboelastography (TEG) tests, as well as coagulogram screening tests (APTT, PT, INR, and fibrinogen) were performed in 136 patients with COVID-19 observed in a hospital setting. All patients received low molecular weight heparins at therapeutic dosages relatively to body weight in accordance with the hospital protocol for patients with COVID-19.

RESULTS

In patients prior to treatment, marked hypercoagulability was observed in all global tests. The main parameters of TD (clot growth rate Vi and Vs) exceeded the reference range in more than 83% and 75% of patients, respectively. Citrate native TEG parameters (R, K, angle α and MA) also showed hyper-coagulation before anticoagulant therapy initiation in 24%, 17%, 48% and 53% of patients, respectively. After the start of treatment, a significant heparin response was obtained for the Vs parameter (the most sensitive to heparin parameter of TD): in 75% of cases, TD recorded hypo-coagulation, in 15% — normocoagulation, and in 10% of measurements, TD parameters continued to be in the hyper-coagulation range. The TEG parameter most sensitive to heparin (angle α) showed a lower response to heparin: it registered hypo-coagulation only in 25% of measurements, in 60% — normocoagulation, and in 15% the parameter was in the hyper-coagulation range.

CONCLUSION

The significant share of hypercoagulant results (10-15%) may indicate that some patients have not achieved a sufficient anticoagulant effect under the therapy.