Background: Coagulation abnormalities in severe COVID-19 patients have not been addressed in depth.
Methods: Prospective longitudinal single-center study involving COVID-19 patients admitted to the ICU. Conventional coagulation tests (prothrombin time, international normalized ratio and activated partial thromboplastin time), rotational thromboelastometry (ROTEM), platelet function, plasma fibrinolysis markers, antithrombin, protein C and S were measured at the time of study inclusion (baseline), and at days 1, 3, 7 and 14 after enrollment. Based on median total maximum SOFA score, patients were divided in two groups: SOFA ≤ 10 and SOFA > 10.
Results: From March, 2020 through May, 2020, 30 patients [median (IQR) age: 61 (52-83) yrs; SAPS III score: 49 (41-61) points] were included in this study. Conventional coagulation tests remained unchanged during the study period, while the majority of patients exhibited a hypercoagulability state based on ROTEM. Fibrinogen levels were increased in both groups. ROTEM (INTEM and EXTEM) maximum clot firmness increased in both study groups from day 0 to day 14. ROTEM – FIBTEM maximum clot firmness was high in both groups during the study period, with a slight decrease from day 0 to day 14 in group SOFA ≤ 10 and a slight increase during the same period in group SOFA > 10. Fibrinolysis (INTEM and EXTEM maximum lysis) was low and decreased over time in all groups, with the most pronounced decrease observed in INTEM maximum lysis in group SOFA > 10. Antithrombin slightly increased over time in group SOFA ≤ 10 while it remained stable in group SOFA > 10. Protein C plasma levels increased over time in both groups, although patients in group SOFA > 10 exhibited lower values in comparison to patients in group SOFA ≤ 10. Protein S plasma levels were low in both groups at baseline and increased over time with no between-group differences.
Conclusion: COVID-19 patients have a pronounced hypercoagulability state, characterized by impaired endogenous anticoagulation and decreased fibrinolysis. The magnitude of coagulation abnormalities seems to correlate with the severity of organ dysfunction. The hypercoagulability state of COVID-19 patients was detected by ROTEM, but not with conventional coagulation tests.