ThrombolysisCLEAR-DVTNCT03901872
Contemporary Endovascular Therapies in Treatment of Acute Iliofemoral Deep Vein Thrombosis
An observational study of Thrombolysis and Deep Vein Thrombosis, run by Guy's and St Thomas' NHS Foundation Trust at 1 site in United Kingdom.
Trial summary
The goal of this initial proof of principle single arm cohort trial is to determine if contemporary endovascular venous intervention, compared with a 1:1 propensity-matched medical therapy arm of the ATTRACT trial, significantly reduces the 2-year occurrence of Post Thrombotic Syndrome (PTS) in subjects with… Read more about this study
- Who is it for?
- Ages 16 to 75 years
- Conditions the study is for
- Thrombolysis, Deep Vein Thrombosis
- What is being tested?
- Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysis
- Type of treatment
- Injection or infusion, Medical device
- How many people
- 65 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 29 Mar 2019to Feb 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
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 16 to 75 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: All acute DVT patients will be screened for entry into the trial
Who may be able to join
- Patient age 16 years to 75 years.
- Onset of acute DVT symptoms of 14 days or less in the study limb.
- DVT located in the common and/or external iliac, or common femoral vein
- Consent to participate in this research study and be willing to commit to study requirements including completion of questionnaires and follow-up visits.
Who cannot join
- In the index leg: established PTS, or previous symptomatic DVT within the last 2 years.
- In the contralateral (non-index) leg: symptomatic acute DVT a) involving the iliac and/or common femoral vein; or b) for which thrombolysis is planned as part of initial therapy.
- Limb-threatening circulatory compromise.
- Pulmonary embolism defined as either massive (Systolic blood pressure < 90 mmHg and/or patient on IV vasoactive medication to support blood pressure), or intermediate high risk pulmonary embolism (PE), as defined by the European Society Guideline on management of PE. Low risk PE and/or intermediate low risk PE can be enrolled.
- Inability to tolerate contemporary venous intervention procedure due to severe dyspnea or acute systemic illness.
- Allergy, hypersensitivity, or thrombocytopenia from heparin, Recombinant tissue plasminogen activator (rtPA), or iodinated contrast, except for mild-moderate contrast allergies for which steroid pre-medication can be used.
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- Haemoglobin < 9.0 mg/dl, INR > 1.6 before starting anticoagulation, or platelets < 100,000/ml. Moderate renal impairment in diabetic patients (estimated glomerular filtration rate < 60 ml/min) or severe renal impairment in non-diabetic patients (estimated glomerular filtration rate < 30 ml/min).
- Active bleeding, recent (< 3 mo) GI bleeding, severe liver dysfunction, bleeding diathesis.
- Recent (< 3 mo) internal eye surgery or haemorrhagic retinopathy; recent (< 10 days) major surgery, cataract surgery, trauma, cardiopulmonary resuscitation, obstetrical delivery, or other invasive procedure.
- History of stroke or intracranial/intraspinal bleed, tumor, vascular malformation, aneurysm.
- Active cancer (metastatic, progressive, or treated within the last 6 months). Exception: patients with non-melanoma primary skin cancers are eligible to participate in the study.
- Severe hypertension on repeated readings (systolic blood pressure > 180 mmHg or diastolic blood pressure > 105 mmHg). This can be treated, and blood pressure must be stable before venous access is obtained (systolic blood pressure <140 mmHg).
- Pregnant (positive pregnancy test, women of childbearing potential must be tested).
- Recently (< 1 mo) had thrombolysis or is participating in another investigational device or drug study that may convolute study results.
- Life expectancy < 2 years or chronic non-ambulatory status.
- Inability to provide informed consent or to comply with study assessments (e.g. due to cognitive impairment or geographic distance).
- Inferior vena cava (IVC) thrombus. Significant thrombus of the IVC, by definition, thrombus extending more than one centimeter above the IVC - common iliac vein confluence will be a cause for exclusion.
- Inability to obtain access of the enrolled ipsilateral popliteal vein using ultrasound guided micro-puncture technique.
- History of, or active heparin induced thrombocytopenia (HIT).
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site, 1 recruiting
- Recruiting
Guy's & St Thomas' NHS Foundation Trust
London, SE1 7EH
Audrey Hau, 02071887188 ext. 53821, audrey.hau@gstt.nhs.uk
About this study
Official title: Contemporary Endovascular Therapies in Treatment of Acute Iliofemoral Deep Vein Thrombosis A Prospective, Multicentre Cohort Trial A Physician Initiated Research Study Request
The goal of this initial proof of principle single arm cohort trial is to determine if contemporary endovascular venous intervention, compared with a 1:1 propensity-matched medical therapy arm of the ATTRACT trial, significantly reduces the 2-year occurrence of Post Thrombotic Syndrome (PTS) in subjects with symptomatic proximal Deep Vein Thrombosis (DVT).
Read the detailed description
A single arm cohort will serve as a proof of principle study, and be the foundation for a larger subsequent prospective, Randomised Clinical Trial (RCT). The aim of this initial single arm cohort is to both validate that contemporary catheter directed therapy performed by experienced operators has significant efficacy and safety at 10 days, 30 days, 6 months, 12 months, and 2 years (details below). If a strong signal of efficacy and safety is found in the initial single arm cohort at 30 days and 6 months, this will provide objective evidence to move forward with a larger multicentre, prospective, RCT.
If the results of the initial single arm proof of principle cohort do not show efficacy, or there is a safety issue, a larger prospective, RCT will not be performed.
- Conditions
- Thrombolysis, Deep Vein Thrombosis
- Being tested
- Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysis
- Medical subject headings
- Venous Thrombosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysisDevice
All patients will undergo ultrasound guided micro puncture venous access of the enrolled ipsilateral lower extremity popliteal vein followed by a diagnostic venogram to define thrombus burden and anatomic extent of DVT. Prior to and every 30 minutes during the endovascular procedure, an activated clotting time (ACT) will be obtained. Intravenous unfractionated heparin will be administered to keep the ACT between 250 - 300. A Zelante catheter will be utilised to perform pharmacomechanical thrombolysis of the enrolled lower extremity. If there is involvement of the popliteal and/or femoral vein, pharmacomechanical thrombolysis should also be performed of these veins. Venous stenting may be implemented to address areas of residual venous stenosis or outflow obstruction following pharmacomechanical thrombolysis. Stent placement in the common iliac, external iliac, and common femoral vein are routinely done to address inflow or outflow issues after pharmacomechanical thrombolysis.
| Study group | Role | What they receive |
|---|---|---|
| Acute Iliofemoral DVT | Suitable patients would be invited to take part in this trial as part of standard of care. Receives: Device: Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of Post thrombotic Syndrome at 2 years
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Apr 2019
- Study start29 Mar 2019
- Primary completionFeb 2023 (estimated)
- Study completionFeb 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ThrombolysisStudies of the same condition, open and under way.
- More trials run by Guy's and St Thomas' NHS Foundation TrustThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Guy's and St Thomas' NHS Foundation Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03901872
- Sponsor's protocol ID
- IRAS 254427
- Acronym
- CLEAR-DVT
- Status last verified
- Apr 2019
- First submitted
- 2 Apr 2019
- Last updated
- 2 Aug 2019
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 2 Aug 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Contemporary Endovascular Therapies in Treatment of Acute Iliofemoral Deep Vein Thrombosis A Prospective, Multicentre Cohort Trial A Physician Initiated Research Study Request
- ClinicalTrials.gov ID
- NCT03901872
- Acronym / sponsor ID
- CLEAR-DVT / IRAS 254427
- Conditions
- Thrombolysis, Deep Vein Thrombosis
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- Guy's and St Thomas' NHS Foundation TrustUniversity, hospital or other
- Study start
- 29 Mar 2019 (actual)
- Primary completion
- Feb 2023 (estimated)
- Study completion
- Feb 2023 (estimated)
- First posted
- 3 Apr 2019 (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.
The goal of this initial proof of principle single arm cohort trial is to determine if contemporary endovascular venous intervention, compared with a 1:1 propensity-matched medical therapy arm of the ATTRACT trial, significantly reduces the 2-year occurrence of Post Thrombotic Syndrome (PTS) in subjects with symptomatic proximal Deep Vein Thrombosis (DVT).
Detailed description
A single arm cohort will serve as a proof of principle study, and be the foundation for a larger subsequent prospective, Randomised Clinical Trial (RCT). The aim of this initial single arm cohort is to both validate that contemporary catheter directed therapy performed by experienced operators has significant efficacy and safety at 10 days, 30 days, 6 months, 12 months, and 2 years (details below). If a strong signal of efficacy and safety is found in the initial single arm cohort at 30 days and 6 months, this will provide objective evidence to move forward with a larger multicentre, prospective, RCT.
If the results of the initial single arm proof of principle cohort do not show efficacy, or there is a safety issue, a larger prospective, RCT will not be performed.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Acute Iliofemoral DVT | – | Device: Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysisSuitable patients would be invited to take part in this trial as part of standard of care. |
Who may qualify
- Ages
- 16 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- All acute DVT patients will be screened for entry into the trial
Key inclusion criteria (4 listed)
- Patient age 16 years to 75 years.
- Onset of acute DVT symptoms of 14 days or less in the study limb.
- DVT located in the common and/or external iliac, or common femoral vein
- Consent to participate in this research study and be willing to commit to study requirements including completion of questionnaires and follow-up visits.
Key exclusion criteria (19 listed)
- In the index leg: established PTS, or previous symptomatic DVT within the last 2 years.
- In the contralateral (non-index) leg: symptomatic acute DVT a) involving the iliac and/or common femoral vein; or b) for which thrombolysis is planned as part of initial therapy.
- Limb-threatening circulatory compromise.
- Pulmonary embolism defined as either massive (Systolic blood pressure < 90 mmHg and/or patient on IV vasoactive medication to support blood pressure), or intermediate high risk pulmonary embolism (PE), as defined by the European Society Guideline on management of PE. Low risk PE and/or intermediate low risk PE can be enrolled.
- Inability to tolerate contemporary venous intervention procedure due to severe dyspnea or acute systemic illness.
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 |
|---|---|---|
| Contemporary endovascular venous intervention by Zelante pharmacomechanical thrombolysisAll patients will undergo ultrasound guided micro puncture venous access of the enrolled ipsilateral lower extremity popliteal vein followed by a diagnostic venogram to define thrombus burden and anatomic extent of DVT. Prior to and every 30 minutes during the endovascular procedure, an activated clotting time (ACT) will be obtained. Intravenous unfractionated heparin will be administered to keep the ACT between 250 - 300. A Zelante catheter will be utilised to perform pharmacomechanical thrombolysis of the enrolled lower extremity. If there is involvement of the popliteal and/or femoral vein, pharmacomechanical thrombolysis should also be performed of these veins. Venous stenting may be implemented to address areas of residual venous stenosis or outflow obstruction following pharmacomechanical thrombolysis. Stent placement in the common iliac, external iliac, and common femoral vein are routinely done to address inflow or outflow issues after pharmacomechanical thrombolysis. | Device | Acute Iliofemoral DVT |
Primary outcome
Rate of Post thrombotic Syndrome at 2 years
Time frame: 2 years
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Aug 2019.
- Individual participant dataSharing planned: Undecided
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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. This study is not recruiting at the moment.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Thrombolysis and Deep Vein Thrombosis, run by Guy's and St Thomas' NHS Foundation Trust 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 4 inclusion and 19 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: status not confirmed, as of the sponsor's last update on 2 Aug 2019. 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.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Audrey Hau (02071887188 ext. 53821, audrey.hau@gstt.nhs.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of Post thrombotic Syndrome at 2 years (time frame: 2 years). 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 2 Aug 2019; AzTrials last refreshed its copy on 8 Nov 2026.