Rivaroxaban Beyond 6 Weeks: Enhancing Outcomes in Isolated Distal Deep Vein Thrombosis

Quick Takes

  • Extending rivaroxaban for an additional 6 weeks in patients with isolated distal deep vein thrombosis who have completed an initial uneventful 6 weeks of anticoagulation reduces the risk of recurrent venous thromboembolism over the following 24 months without increasing the risk of major bleeding.

The optimal management of isolated, distal deep vein thrombosis (DVT) remains unclear. Data from recent studies suggest that certain patients may benefit from anticoagulation, especially in the presence of risk factors, including extensive clot burden, severe symptoms, or underlying hypercoagulable states. However, the optimal duration of anticoagulation remains unknown.

Ageno et al. conducted a randomized, double-blind, placebo-controlled trial to compare two different durations of rivaroxaban treatment in patients with symptomatic isolated distal DVT.1

Patients were excluded if they had any of the following statuses: pregnant, breastfeeding, active cancer, concomitant proximal DVT or symptomatic pulmonary embolism (PE), severe kidney insufficiency, severe liver insufficiency, or any other contraindication to rivaroxaban.

After receiving the standard dose of rivaroxaban for 6 weeks, 402 participants were randomly assigned to receive either rivaroxaban 20 mg (n = 200) or placebo (n = 202) once daily for an additional 6 weeks. The patients were followed for 24 months. The mean age was 65 years, and women represented 58% of both cohorts.

The primary efficacy outcome was recurrent venous thromboembolism (VTE) for 24 months following randomization and was defined as the composite of progression of the index, isolated distal DVT, recurrent isolated distal DVT, new proximal DVT, symptomatic PE, or fatal PE. The primary safety outcome was major bleeding (defined according to the International Society of Thrombosis and Haemostasis [ISTH] criteria) up to 2 days after the last dose of rivaroxaban or placebo.

The primary efficacy outcome occurred in 11% of patients in the rivaroxaban arm and in 19% in the placebo arm (relative risk 0.59; 95% confidence interval, 0.36-0.95; p = 0.03; number needed to treat, 13). No major bleeding events occurred in either cohort, although 0.5% of patients experienced clinically relevant nonmajor bleeding events. However, three major bleeding events occurred in the prerandomization period (one intracranial hemorrhage and two vaginal bleeds resulting in a drop in hemoglobin levels of >2 g/dL) in both cohorts.

The findings of this randomized controlled trial suggest that an additional 6 weeks of rivaroxaban in patients with isolated distal DVT who have completed an initial uneventful 6 weeks of anticoagulation reduces the risk of recurrent VTE over the following 24 months without increasing the risk of major bleeding.

References

  1. Ageno W, Bertù L, Bucherini E, et al.; RIDTS Study Group. Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial. BMJ 2022;379:[ePub ahead of print].

Resources

Clinical Topics: Anticoagulation Management, Pulmonary Hypertension and Venous Thromboembolism, Vascular Medicine, Anticoagulation Management and Venothromboembolism

Keywords: Rivaroxaban, Venous Thrombosis, Anticoagulation Management, Anticoagulants, Venous Thromboembolism