COVID-19 Antithrombotic Rivaroxaban Evaluation

There are several ways in which the COVID-19 pandemic may affect the prevention and management of thrombotic and thromboembolic disease, either direct effect or the indirect effects of infection, such as through severe illness and hypoxia, may predispose patients to thrombotic events. The severe inflammatory response, critical illness, and underlying traditional risk factors may all predispose to thrombotic events. Therefore, considering the high-risk profile of cardiovascular comorbidities in patients with COVID-19, it is scientifically relevant to evaluate the use of anticoagulants as an adjunctive treatment in the context of COVID-19. Indeed, it will be tested the hypothesis that the use of moderate dose of rivaroxaban has a beneficial effect in the treatment of patients with a confirmed or probable diagnosis of COVID-19 infection, with no clear indication for hospitalization (mild and moderate cases) upon initial medical care, by reducing the need of hospitalization due to complications related to COVID-19.

Initial studies suggest an inflammatory state and hypercoagulation in individuals with COVID-19. Apparently, the fact that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to Angiotensin Converting Enzyme 2 (ACE2) receptors can lead to ACE2 depletion by SARS-CoV-2 favoring the "harmful" ACE1 / angiotensin II and promoting tissue damage, including stroke. Recent observational studies indicate a higher rate of thromboembolism in patients with COVID-19, especially those in severe condition. They also report that, in patients treated with anticoagulants, complication rates were lower as compared with those not receiving anticoagulant therapies. More recently, in a post-mortem study of patients with Covid-19 compared to recently published cases of influenza, the histopathological pattern on the periphery of the lungs of patients with Covid-19 revealed a diffuse alveolar lesion with infiltration of perivascular T cells and other vascular aspects, consisting of severe endothelial damage (endothelitis) associated with the presence of intracellular viruses and broken cell membranes. In addition, pulmonary vessels showed generalized thrombosis with microangiopathy, and alveolar capillary microthrombi were much more frequent in patients with COVID-19 than with severe influenza respiratory conditions.