Venous ThromboembolismPhase 4THRIVENCT05735639
THRomboprophylaxis in Individuals Undergoing Superficial endoVEnous Treatment (THRIVE)
A Phase 4 study testing Dalteparin Sodium, Tinzaparin Sodium and Enoxaparin Sodium in people with Venous Thromboembolism and Varicose Veins, run by Imperial College London at 1 site in United Kingdom.
Trial summary
Endovenous interventions are keyhole operations for varicose veins that are carried out from within the vein itself. Varicose veins are enlarged veins close to the surface of the skin. They are connected to the bigger deeper veins in the leg (known as deep veins). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Venous Thromboembolism, Varicose Veins
- What is being tested?
- Dalteparin Sodium, Tinzaparin Sodium and Enoxaparin Sodium
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 3,175 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 22 Jan 2024to 31 Dec 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults (>18 years)
- Scheduled to undergo endovenous intervention of truncal varicose veins under local anaesthesia
- Treatment technologies including radiofrequency, laser, mechanochemical, foam sclerotherapy and cyanoacrylate glue
Who cannot join
- Clinical indication for therapeutic anticoagulation e.g., atrial fibrillation
- Previous personal or first-degree relative history of VTE
- Thrombophilia
- Female patients of childbearing potential who have a positive pregnancy test
- A history of allergy to heparins or direct oral anticoagulants
- A history of heparin-induced thrombocytopenia
Show all 14Show fewer
- Inherited and acquired bleeding disorders
- Evidence of active bleeding
- Concomitant major health problems such as active cancer and chronic renal and/or liver impairment
- Known thrombocytopenia (platelets known to be less than 50 x 109
- /l)
- Surgery or major trauma in the previous 90 days
- Recent ischemic stroke in the previous 90 days
- Inability to provide consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Imperial College Hospital NHS Foundation Trust
London, W6 8RF
Alun H Davies
About this study
Official title: THRomboprophylaxis in Individuals Undergoing Superficial endoVEnous Treatment (THRIVE) - a Multi-centre Assessor-blind Randomised-controlled Trial
Endovenous interventions are keyhole operations for varicose veins that are carried out from within the vein itself. Varicose veins are enlarged veins close to the surface of the skin. They are connected to the bigger deeper veins in the leg (known as deep veins). Because of this, operations to close the varicose veins can increase the chance of a blood clot forming in the deep veins. Blood clots in the deep veins happen in around 1 in 50 people after endovenous operations. A clot in the leg can cause swelling, pain, and other long-term problems. If a clot in the leg breaks off and travels to the lungs, it can cause problems with the lung' ability to move oxygen from the air into the blood and may, in rare cases, be life threatening.
Varicose vein procedures may carry a slightly higher risk of blood clot formation, and we are currently unsure if current clot reducing medicines are beneficial in preventing blood clots in people having varicose vein procedures.
This study will investigate if it is worthwhile prescribing medicines to reduce blood clots after varicose vein procedures.
- Conditions
- Venous Thromboembolism, Varicose Veins
- Being tested
- Dalteparin Sodium, Tinzaparin Sodium, Enoxaparin Sodium, Rivaroxaban, Apixaban
- Medical subject headings
- Venous Thromboembolism, Varicose Veins
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dalteparin SodiumDrug
Low molecular weight heparin
Tinzaparin SodiumDrug
Low molecular weight heparin
Enoxaparin SodiumDrug
Low molecular weight heparin
RivaroxabanDrug
Direct oral anticoagulant
ApixabanDrug
Direct oral anticoagulant
Dabigatran EtexilateDrug
Direct oral anticoagulant
| Study group | Role | What they receive |
|---|---|---|
| Compression therapy alone | No intervention | Not described |
| Compression therapy + single dose of low-molecular weight heparin at time of procedure | Experimental | A single prophylactic dose of low molecular weight heparin (LMWH) (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) will be prescribed as per standard practice and administered in accordance with the relevant Summary of Product Characteristics (SmPC), manufacturer's recommendations and instructions for use. Receives: Drug: Dalteparin Sodium; Drug: Tinzaparin Sodium; Drug: Enoxaparin Sodium |
| Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC | Experimental | An extended duration of LMWH (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) or an extended duration of a direct oral anticoagulant (DOAC) (e.g., rivaroxaban, apixaban, dabigatran etexilate) will be prescribed as per current local practice and administered in accordance with the relevant SmPC, manufacturer's recommendations and instructions for use. The duration of this must be at least 7 days, but can be in line with local practice i.e., 7, 10 or 14 days. Receives: Drug: Dalteparin Sodium; Drug: Tinzaparin Sodium; Drug: Enoxaparin Sodium; Drug: Rivaroxaban; Drug: Apixaban; Drug: Dabigatran Etexilate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Imaging confirmed lower limb deep vein thrombosis (DVT) with or without symptoms, or pulmonary embolism (PE) with symptoms within 90 days of varicose vein treatment.
The rate of lower limb DVT with or without symptoms, or PE with symptoms within 90 days of varicose vein treatment.
Measured: 90 days
Secondary outcomes (8)
Lower limb DVT without symptoms
Duplex ultrasound scan
Measured: 21 - 28 days
Lower limb DVT with symptoms
Self-reported VTE outcome questionnaire
Measured: 90 days
PE with symptoms
VTE outcome questionnaire (self-reported) to determine the rate of PE
Measured: 90 days
Comparisons of quality of life at 7- and 90-days post-procedure
Using EQ-5D
Measured: 90-days
Cost-effectiveness of providing pharmacological thromboprophylaxis
Incremental Cost-Effectiveness Ratio (ICER)
Measured: 90 days
Exploratory analyses to assess how well a VTE risk assessment tool predicts VTE outcome
Venous thromboembolism risk as determined by the Department of Health Risk Assessment tool
Measured: 90 days
Exploratory analyses to assess how well a VTE risk assessment tool predicts VTE outcome
Venous thromboembolism risk as determined by the Caprini risk assessment model
Measured: 90 days
Mortality rates in each group
Rate of mortality
Measured: 90 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Feb 2023
- Study start22 Jan 2024
- Primary completion30 Jun 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Venous ThromboembolismStudies of the same condition, open and under way.
- More trials run by Imperial College LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 3,175 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Imperial College London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05735639
- Sponsor's protocol ID
- 22CX7510
- Other IDs
- ISRCTN18501431
- Acronym
- THRIVE
- Status last verified
- Jun 2026
- First submitted
- 19 Jan 2023
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- THRomboprophylaxis in Individuals Undergoing Superficial endoVEnous Treatment (THRIVE) - a Multi-centre Assessor-blind Randomised-controlled Trial
- ClinicalTrials.gov ID
- NCT05735639
- Acronym / sponsor ID
- THRIVE / 22CX7510
- Conditions
- Venous Thromboembolism, Varicose Veins
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 3,175 participants (estimated)
- Lead sponsor
- Imperial College LondonUniversity, hospital or other
- Study start
- 22 Jan 2024 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 21 Feb 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Endovenous interventions are keyhole operations for varicose veins that are carried out from within the vein itself. Varicose veins are enlarged veins close to the surface of the skin. They are connected to the bigger deeper veins in the leg (known as deep veins). Because of this, operations to close the varicose veins can increase the chance of a blood clot forming in the deep veins. Blood clots in the deep veins happen in around 1 in 50 people after endovenous operations. A clot in the leg can cause swelling, pain, and other long-term problems. If a clot in the leg breaks off and travels to the lungs, it can cause problems with the lung' ability to move oxygen from the air into the blood and may, in rare cases, be life threatening.
Varicose vein procedures may carry a slightly higher risk of blood clot formation, and we are currently unsure if current clot reducing medicines are beneficial in preventing blood clots in people having varicose vein procedures.
This study will investigate if it is worthwhile prescribing medicines to reduce blood clots after varicose vein procedures.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Compression therapy alone | No intervention | – |
| Compression therapy + single dose of low-molecular weight heparin at time of procedure | Experimental | Drug: Dalteparin Sodium, Drug: Tinzaparin Sodium, Drug: Enoxaparin SodiumA single prophylactic dose of low molecular weight heparin (LMWH) (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) will be prescribed as per standard practice and administered in accordance with the relevant Summary of Product Characteristics (SmPC), manufacturer's recommendations and instructions for use. |
| Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC | Experimental | Drug: Dalteparin Sodium, Drug: Tinzaparin Sodium, Drug: Enoxaparin Sodium, Drug: Rivaroxaban, Drug: Apixaban, Drug: Dabigatran EtexilateAn extended duration of LMWH (e.g., dalteparin sodium, tinzaparin sodium, enoxaparin sodium) or an extended duration of a direct oral anticoagulant (DOAC) (e.g., rivaroxaban, apixaban, dabigatran etexilate) will be prescribed as per current local practice and administered in accordance with the relevant SmPC, manufacturer's recommendations and instructions for use. The duration of this must be at least 7 days, but can be in line with local practice i.e., 7, 10 or 14 days. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Adults (>18 years)
- Scheduled to undergo endovenous intervention of truncal varicose veins under local anaesthesia
- Treatment technologies including radiofrequency, laser, mechanochemical, foam sclerotherapy and cyanoacrylate glue
Key exclusion criteria (14 listed)
- Clinical indication for therapeutic anticoagulation e.g., atrial fibrillation
- Previous personal or first-degree relative history of VTE
- Thrombophilia
- Female patients of childbearing potential who have a positive pregnancy test
- A history of allergy to heparins or direct oral anticoagulants
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dalteparin SodiumLow molecular weight heparin | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC, Compression therapy + single dose of low-molecular weight heparin at time of procedure |
| Tinzaparin SodiumLow molecular weight heparin | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC, Compression therapy + single dose of low-molecular weight heparin at time of procedure |
| Enoxaparin SodiumLow molecular weight heparin | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC, Compression therapy + single dose of low-molecular weight heparin at time of procedure |
| RivaroxabanDirect oral anticoagulant | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC |
| ApixabanDirect oral anticoagulant | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC |
| Dabigatran EtexilateDirect oral anticoagulant | Drug | Compression therapy + single dose of LMWH at time of procedure + extended course of LMWH or DOAC |
Primary outcome
Imaging confirmed lower limb deep vein thrombosis (DVT) with or without symptoms, or pulmonary embolism (PE) with symptoms within 90 days of varicose vein treatment.
Time frame: 90 days
The rate of lower limb DVT with or without symptoms, or PE with symptoms within 90 days of varicose vein treatment.
8 secondary outcomes
Lower limb DVT without symptoms
Time frame: 21 - 28 days
Lower limb DVT with symptoms
Time frame: 90 days
PE with symptoms
Time frame: 90 days
Comparisons of quality of life at 7- and 90-days post-procedure
Time frame: 90-days
Cost-effectiveness of providing pharmacological thromboprophylaxis
Time frame: 90 days
Exploratory analyses to assess how well a VTE risk assessment tool predicts VTE outcome
Time frame: 90 days
Exploratory analyses to assess how well a VTE risk assessment tool predicts VTE outcome
Time frame: 90 days
Mortality rates in each group
Time frame: 90 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2026.
- Individual participant dataSharing planned: No
Related trials for Venous Thromboembolism
RecruitingPhase 3
REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults
Venous Thromboembolism (VTE)
RecruitingPhase 3
Treatment and Secondary Prevention of Venous Thromboembolism (VTE) in Adult Participants With Solid and Hematologic Cancers
Venous Thromboembolism (VTE)
RecruitingPhase 3
REGN7508 in Adult Participants for Prevention of Cancer-Associated Thrombosis
Cancer-Associated Thrombosis (CAT)
RecruitingPhase 3
REGN7508 Versus Acetylsalicylic Acid (ASA) for Venous Thromboprophylaxis After Total Knee Arthroplasty in Adult Participants
Symptomatic Venous Thromboembolism (VTE)
Recruiting
DEFIANCE: RCT of ClotTriever System Versus Anticoagulation In Deep Vein Thrombosis
Venous Thromboembolism, Deep Venous Thrombosis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Dalteparin Sodium, Tinzaparin Sodium and Enoxaparin Sodium in people with Venous Thromboembolism and Varicose Veins, run by Imperial College London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sarah Whittley (+442033117309, s.whittley@imperial.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Imaging confirmed lower limb deep vein thrombosis (DVT) with or without symptoms, or pulmonary embolism (PE) with symptoms within 90 days of varicose vein treatment. (time frame: 90 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2026.