Rivaroxaban cuts blood clot risk after COVID-19 hospital discharge

Reuters Health - 22/12/2021 - After hospital discharge for COVID-19, extended anticoagulation with a low-dose of rivaroxaban may cut the risk of venous thromboembolism (VTE) without major bleeding in patients at high-risk for VTE, new research suggests.

"The MICHELLE trial is the first randomized trial to provide high-quality data of an important 67% reduction in thrombosis and cardiovascular death in the post-hospital discharge period using a direct oral anticoagulant rivaroxaban in high-risk COVID inpatients using a validated VTE risk score, IMPROVE," Dr. Alex C. Spyropoulos of the Feinstein Institutes for Medical Research in Manhasset, New York, told Reuters Health by email.

There currently is no consensus on the role of extended thromboprophylaxis after COVID-19 discharge.

As reported in The Lancet, the MICHELLE trial enrolled 320 patients hospitalized with COVID-19 at increased risk for VTE defined as an IMPROVE VTE score of at least 4 or 2-3 with D-dimer level above 500 ng/mL.

All patients received standard doses of heparin during their hospital stay. At discharge, half were randomly assigned to receive rivaroxaban (10 mg/day) and half to receive no anticoagulation. Two patients (one in each group) withdrew consent and were not included in the intention-to-treat primary analysis.

The primary efficacy outcome was a composite of symptomatic or fatal VTE, asymptomatic VTE on bilateral lower-limb venous ultrasound and CT pulmonary angiogram, symptomatic arterial thromboembolism, and cardiovascular death at day 35.

This outcome occurred in five (3%) of 159 patients on rivaroxaban versus 15 (9%) of 159 not on anticoagulation (relative risk, 0.33; 95% CI, 0.12 to 0.90).

No major bleeding occurred in either study group. Two patients taking rivaroxaban (1%) had allergic reactions. The results were consistent across all prespecified subgroups.

"Extended post discharge thromboprophylaxis should now be considered standard of care in hospitalized COVID patients with an IMPROVE VTE score of 4 or more, or a score of 2 or 3 and elevated D dimers," Dr. Spyropoulos told Reuters Health.

This trial was an investigator-initiated study with financial support from Science Valley Research Institute Brazil and Bayer, which provided the study drug and partial financial support. Dr. Spyropoulos and several co-authors have financial relationships with Bayer and other pharmaceutical companies.

SOURCE: https://bit.ly/3q8muB2 Lancet, online December 15, 2021.

By Megan Brooks



Posted on 22 December 202112 January 2022