ABSTRACT
Background : Covid-19 infection is associated with a widespread global activation of coagulation and affected patients are at an increased risk of thrombosis. Aims : Heparin therapy is effective in various setting in preventing thromboembolic complications and aim of this study was to assess heparin response in COVID-19 patients through anti-FXa test. Methods : In 52 patients, M:F ratio 59:41, median age 59 years old, admitted in different intensity of care units of our hospital, treated with different regimens of heparin (100 U/kg every 24 h in low intensity care, 70 U/kg every 12 h in intermediate intensity care and 100 U/kg every 12 h in intensive care unit), anti-FXa levels were measured immediately before and 3 h after subcutaneous enoxaparin administration. On the same samples thrombin generation tests were performed. Results : Patients treated with 100 U/kg every 24 h and 70 U/ kg every 12 h had median anti-FXa basal levels in the prophylactic range, respectively 0.18 and 0.22 U/ml, while patients treated with 100 U/kg every 12 h were in the anticoagulant range (0.37 U/ ml). Despite heparin therapy thrombin generation was elevated in COVID-19 patients, indicating a high level of coagulation activation. Conclusions : In conclusion we demonstrated that the biological response to enoxaparin in COVID-19 patients is in the expected range using anti-FXa assay and patients are not resistant to heparin therapy.