Medically Ill Hospitalized Patients for COVID-19 Thrombosis Extended Prophylaxis With Rivaroxaban Therapy - MICHELLE

Contribution To Literature:

The MICHELLE trial showed that rivaroxaban after hospitalization for COVID-19 improved clinical outcomes without increasing bleeding.


The goal of the trial was to evaluate rivaroxaban compared with control among patients discharged after hospitalization for coronavirus disease 2019 (COVID-19) infection.

Study Design

  • Randomization
  • Parallel

Participants discharged after COVID-19 infection were randomized to rivaroxaban 10 mg daily (n = 160) versus control (n = 160).

  • Total number of enrollees: 320
  • Duration of follow-up: 35 days
  • Mean patient age: 58 years
  • Percentage female: 39%

Inclusion criteria:

  • ≥18 years of age
  • Hospitalized for minimum of 3 days with COVID-19 infection
  • On standard-dose thromboprophylaxis
  • Total modified IMPROVE venous thromboembolism (VTE) Risk Score ≥4, or
  • Total modified IMPROVE VTE Risk Score 2 or 3 and D-dimer >500 ng/ml

Exclusion criteria:

  • Any bleeding within the last 3 months
  • Surgery, biopsy, or trauma within the last 4 weeks or planned
  • Required anticoagulation after discharge
  • Use of dual antiplatelet therapy during hospitalization
  • Chronic kidney disease

Principal Findings:

The primary outcome, composite of symptomatic VTE, VTE-related death, bilateral VTE, symptomatic arterial thromboembolism, myocardial infarction, nonhemorrhagic stroke, major adverse limb event, or cardiovascular death at 35 days, was 3.14% in the rivaroxaban group compared with 9.43% in the control group (p = 0.03).

Secondary outcomes:

  • Incidence of major bleeding according to International Society on Thrombosis and Haemostasis (ISTH) criteria: 0% vs. 0%


Among patients discharged after COVID-19 infection, rivaroxaban for 35 days was beneficial. Rivaroxaban was associated with a reduction in clinical events without increasing major bleeding.


Ramacciotti E, Agati LB, Calderaro D, et al. Rivaroxaban versus no anticoagulation for post-discharge thromboprophylaxis after hospitalization for COVID-19 (MICHELLE): an open-label, multicentre, randomized, controlled trial. Lancet 2021;Dec 15:[Epub ahead of print].

Presented by Dr. Eduardo Ramacciotti at the European Society of Cardiology Virtual Congress, August 29, 2021.

Clinical Topics: Anticoagulation Management, COVID-19 Hub, Prevention, Pulmonary Hypertension and Venous Thromboembolism, Vascular Medicine, Anticoagulation Management and Venothromboembolism

Keywords: ESC Congress, ESC21, Anticoagulants, COVID-19, Hemorrhage, Myocardial Infarction, Patient Discharge, Post-Exposure Prophylaxis, Primary Prevention, Risk Factors, Stroke, Thromboembolism, Thrombosis, Vascular Diseases, Venous Thromboembolism

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