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Deciding together how long to take blood thinners after unprovoked clots

Tests shared choices on blood thinner length after unprovoked venous thromboembolism.

Key facts

Who runs it
University Hospital, Brest
Where
France19 sites in 1 countryChoose a country to see its sites
Trial code
Registry title
Shared Decision-making Process for Unprovoked vEnous THromboEmbolism Management. (ETHER )
Status
Recruiting
People taking part
2,400 people, planned
Started
30 Oct 2025
Expected to end
Oct 2035
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Usual Care Group
  • shared decision-making process
Record updated
28 November 2025

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults after a first blood clot in the lung or deep leg veins with no clear cause. They must already have had 3 to 6 months of blood thinner treatment.

Age
18 years or older
Sex
All sexes
Disease stage
First episode of symptomatic unprovoked pulmonary embolism (clot in the lung) and/or proximal deep vein thrombosis (clot in a deep vein near the trunk). Unprovoked means no clear cause was found.
Earlier treatment
Must have been treated for 3 to 6 uninterrupted months with full dose anticoagulant (blood thinner) therapy. Cannot join if blood thinners were stopped for 14 days or more before joining.

Main reasons for not taking part

  • A clot only in the lower leg veins, or only in small lung arteries (sub-segmental PE)
  • A previous unprovoked clot, or known CTEPH (long-lasting high blood pressure in the lungs from clots)
  • Another reason for blood thinners, such as atrial fibrillation or mechanical heart valves
  • Active cancer of less than 24 months, or life expectancy under 18 months
  • Current pregnancy

The registry criteria, word for word

Show all 14 criteriaShow less

Who can take part

  • Patient > or = 18 years,
  • Patient with a first episode of symptomatic unprovoked pulmonary embolism (PE) and/or proximal deep vein thrombosis (DVT) treated for 3 to 6 uninterrupted months with full dose anticoagulant therapy,
  • Signed informed consent

Who cannot take part

  • Previous unprovoked VTE
  • Active cancer of less than 24 months,
  • Life expectancy <18 months (e.g.; patients with an end-stage chronic disease)
  • Unable or refusal to give informed consent,
  • Isolated distal DVT,
  • Isolated sub-segmental PE
  • Known CTEPH
  • Indication for anticoagulation other than DVT or PE (e.g.; atrial fibrillation, mechanic valves…),
  • Interruption of anticoagulation for 14 days or more before the inclusion,
  • Current pregnancy,
  • Not affiliated to national insurance, social security (only for France)

This trial has no sites in United States.

It has sites in one country. Choose a country to see its sites.

About the trial

What the trial wants to find out

Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) is a frequent disease and the third most common cause of cardiovascular death in the world after myocardial infarction and stroke. Anticoagulant therapy drastically reduces the risk of early VTE recurrence and death, but it exposes patients to a substantial risk of bleeding. Hence, determining the optimal duration of anticoagulant treatment for VTE is a major public health issue.

Read full original descriptionShow less

When major transient risk factors for VTE are identified (major surgery, immobilization...), patients generally do not need to extend anticoagulation beyond 3 months, whereas for VTE diagnosed in the context of cancer, therapeutic anticoagulation is required for as long as the cancer is considered "active".

However, in more than 50% of cases, venous thromboembolic disease occurs spontaneously, i.e. without any significant clinically detectable circumstance (known as unprovoked venous thromboembolic disease). In such patients, the risk of recurrence is high (35% recurrence rate at 5 years, with a 10% risk of death per recurrence). Scientific societies therefore recommend continuing anticoagulant treatment "indefinitely" (i.e. without programming a stop date or long-term treatment). However, this practice exposes these patients to an ongoing, non-negligible increase in the risk of bleeding, which could ultimately exceed the risk of recurrence of venous thrombo-embolic disease.

Optimizing anticoagulant therapy beyond the first three to six months of treatment is therefore a crucial and challenging issue, which could improve the long-term prognosis of patients with unprovoked thromboembolic venous disease.

Based on the quantitative and qualitative approaches implemented in MORPHEUS project granted by European Commission (HORIZON-HLTH-2022-TOOL-11-01 call), the investigators have combined predictive personalized medicine, through the use of risk biomarkers, with a patient-centered model of medicine, which, while based on an understanding of the patient's experience, leading to develop Time-Dependent Multicomponent risk prediction scores and socIo-anthropological scales (TDMI) integrated in a shared decision-making process regarding anticoagulant treatment duration in patients with a first episode of unprovoked VTE.

The aim of this study is to demonstrate that this strategy, based on a medical decision-making process shared between patients and physicians and including TDMI, reduces the risk of recurrence of thromboembolic venous disease (fatal or non-fatal), the risk of bleeding and all-cause mortality, and is associated with greater patient satisfaction after a first episode of unprovoked thromboembolic venous disease.

The 2 groups in the trial

  • Control armExisting treatment, for comparison

    Anticoagulant treatment management according to usual practice and international guidelines

    Treatment: Usual Care Group

  • Experimental armTreatment being tested

    Shared decision-making process integrating time-dependent multicomponent risk prediction scores and socio-anthropological scales (TDMI)

    Treatment: shared decision-making process

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Prognosis Improvement of Unprovoked vEnous THromboEmbolism With the Use of a Shared Decision-making Process Including a Time-dependent Multicomponent Risk Prediction Scores inteRvention.
Plain-language title
Deciding together how long to take blood thinners after unprovoked clotsGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 15 November 2026.
Record updated
28 November 2025