Medically Ill Hospitalized Patients for COVID-19 THrombosis Extended ProphyLaxis With Rivaroxaban ThErapy: The MICHELLE Trial

Inclusion Criteria: * Male and nonpregnant female patients 18 years of age or older * Positive reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay for SARS-CoV-2 in a respiratory tract sample * Pneumonia confirmed by chest imaging * Additional risk factors for VTE, as indicated by a total modified International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) risk score of 4 or higher * Have received thromboprophylaxis with low-molecular-weight heparin, fondaparinux, or unfractionated heparin during the index hospitalization Exclusion Criteria: * Age \< 18 years * Refusal of informed consent * Physician decision that involvement in the trial was not in the patient's best interest * Patients with a medical indication for anticoagulation therapy at the time of inclusion (for example, diagnosis of venous thromboembolism, atrial fibrillation, mechanical valve prosthesis) * Platelets \< 50,000 / mm3 * Patients with contraindications to anticoagulation (active bleeding, liver failure, blood dyscrasia, or prohibitive hemorrhagic risk in the investigator's assessment) * Active cancer (excluding non-melanoma skin cancer) defined as cancer, not in remission or requiring active chemotherapy or adjunctive therapies such as immunotherapy or radiotherapy. * Use of strong inhibitors of cytochrome P450 (CYP) 3A4 and/or glycoprotein P (P-gp) (eg protease inhibitors, ketoconazole, Itraconazole) and/or use of P-gp and strong inducers of CYP3A4 (how but not limiting rifampicin/rifampicin, rifabutin, rifapentine, phenytoin, phenobarbital, carbamazepine or St. John's wort) * Creatinine clearance \<30 ml / min * Pregnancy or breastfeeding * known HIV infection * Presence of one of the following uncontrolled or unstable cardiovascular diseases: stroke, ECG confirmed acute ischemia or myocardial infarction, and/or clinically significant dysrhythmia