Comparison of Two Doses of Enoxaparin for Thromboprophylaxis in Hospitalized COVID-19 Patients (X-Covid 19)

Enoxaparin for Thromboprophylaxis in Hospitalized COVID-19 Patients: Comparison of 40 mg o.d. Versus 40 mg b.i.d. A Randomized Clinical Trial

The purpose of this study is to determine whether a higher dose of low molecular weight heparin (enoxaparin 40 mg b.i.d.) is superior than the standard prophylaxis dose (enoxaparin 40 mg o.d.) in reducing thromboembolic events in COVID-19 patients.

Coronavirus disease-19 (COVID-19 ), which is caused by SARS-CoV-2 infection, are apparently at high risk of venous thromboembolism (VTE), as a consequence of activation of the hemostatic system which, in the most severe cases, can also be associated with the formation of microthrombi and clinically relevant disseminated intravascular coagulation. Concerns about the efficacy of thromboprophylaxis with standard doses of low-molecular-weight heparin (LMWH) has been raised. Therefore, LMWH at higher doses than those recommended for thromboprophylaxis is used in some hospitals, although no evidence exists yet of higher efficacy of high doses compared to standard prophylactic doses. This practice might as well increase the risk of major bleeding. The investigators designed a randomized trial comparing standard prophylactic dose of subcutaneous enoxaparin (40 mg o.d.) with higher dose (40 mg b.i.d) with the aim of testing whether high-dose thromboprophylaxis is more effective than standard dose in preventing VTE in COVID-19 patients.

Open-label Multicentre Prospective Controlled Randomized Trial in patients with SARS-CoV-2 infection. Patients will be randomized 1:1 to 40 mg subcutaneous enoxaparin o.d. versus 40 mg enoxaparin b.i.d within 12 hours after hospitalization.

Deep vein thrombosis events diagnosed by serial compression ultrasonography and pulmonary embolism events diagnosed by computed tomography scan

death, venous thromboembolism, use of mechanical ventilation, stroke, acute myocardial infarction and admission to an intensive care

Maximum sequential organ failure assessment (SOFA) score comparison between the two groups. The SOFA score ranges from 0 to 24. Higher SOFA score is associated with a greater risk of death or prolonged intensive care unit stay.

To compare C-reactive protein levels as % above the upper reference limit [URL]) among the two groups.

To compare the incidence of SARS-CoV-2-related Acute Respiratory Distress Syndrome (ARDS) between the two groups.

To compare measures of right ventricular function at trans-thoracic echocardiography or CT between admission and follow-up, whenever available

Inclusion Criteria: All-comers patients aged >=18 years and admitted to hospital with laboratory-confirmed SARS-CoV-2 infection Exclusion Criteria: Patients admitted directly to an intensive care unit; Estimated creatinine clearance <15 ml/min/1.73m2; Patients needing anticoagulant for prior indication; Participants involved in other clinical trials; Any other significant disease or disorder which, in the opinion of the investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.

Flumignan RL, Civile VT, Tinoco JDS, Pascoal PI, Areias LL, Matar CF, Tendal B, Trevisani VF, Atallah AN, Nakano LC. Anticoagulants for people hospitalised with COVID-19. Cochrane Database Syst Rev. 2022 Mar 4;3(3):CD013739. doi: 10.1002/14651858.CD013739.pub2.

Flumignan RL, Tinoco JDS, Pascoal PI, Areias LL, Cossi MS, Fernandes MI, Costa IK, Souza L, Matar CF, Tendal B, Trevisani VF, Atallah AN, Nakano LC. Prophylactic anticoagulants for people hospitalised with COVID-19. Cochrane Database Syst Rev. 2020 Oct 2;10(10):CD013739. doi: 10.1002/14651858.CD013739.

Levi M, Thachil J, Iba T, Levy JH. Coagulation abnormalities and thrombosis in patients with COVID-19. Lancet Haematol. 2020 Jun;7(6):e438-e440. doi: 10.1016/S2352-3026(20)30145-9. Epub 2020 May 11. No abstract available.