Further clot risk reduced by extending anti-clotting treatment after distal DVT

Giving the anti-clotting drug rivaroxaban to patients for 12 weeks instead of the usual six after a blood clot in the lower leg reduces the risk of further clots developing up to two years after treatment, finds a trial published by The BMJ.

Rivaroxaban is an anticoagulant drug. It's given to people at a high risk of getting dangerous blood clots to help their blood clot (thicken) more slowly.

Anticoagulation is known to prevent further clots developing in patients who have already had a blood clot in their leg, including those with isolated distal deep vein thrombosis (DVT). But doctors are still not sure whether all patients with distal DVT should receive anticoagulation, and for how long.

To address this uncertainty, researchers set out to compare two different treatment durations of rivaroxaban in 402 adults (average age 65; 58% women) diagnosed with isolated distal DVT at 28 specialist outpatient clinics across Italy.

After receiving standard dose rivaroxaban for six weeks, participants who had not developed any clotting or bleeding complications were randomly assigned to receive either rivaroxaban 20 mg or placebo once daily for an additional six weeks. Participants were assessed for new clots or serious bleeding at three weeks, six weeks, three months, and 24 months, and were advised to seek medical advice if new signs or symptoms that potentially suggested recurrent events occurred.

The results show that after randomisation, 23 (11%) patients in the rivaroxaban group and 39 (19%) in the placebo group developed a further clot, either in the lower leg , the upper leg ,or the lung.

Recurrent isolated distal DVT occurred in 16 (8%) patients in the rivaroxaban group and 31 (15%) in the placebo group, while proximal DVT or pulmonary embolism occurred in 7 (3%) patients in the rivaroxaban group and 8 (4%) in the placebo group.

Reference:

Ageno, W. (2022, November 23), Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial, The BMJ, DOI 10.1136/bmj-2022-072623.