Two Weeks of Low Molecular Weight Heparin for Distal Vein Thrombosis (TWISTER)
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ClinicalTrials.gov Identifier: NCT01252420 |
Recruitment Status : Unknown
Verified July 2010 by Monash Medical Centre.
Recruitment status was: Recruiting
First Posted : December 3, 2010
Last Update Posted : December 6, 2010
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Venous Thrombosis Pulmonary Embolism | Drug: Enoxaparin | Phase 4 |
Approximately 50% of symptomatic episodes of deep vein thrombosis (DVT) will be confined to the calf veins (distal DVT). The proportion of distal DVT that propagate to the proximal veins, increasing the risk of pulmonary embolism, is not known. The best treatment of isolated distal DVT is therefore controversial and options include no treatment, follow-up scanning and treatment of only those patients with thrombus propagating to proximal veins, and full anticoagulation for periods ranging from 2 weeks to 3 months.
There is good evidence that the 3-month thromboembolic risk in patients with a negative CUS that is limited to the proximal veins is low, in the order of 1%. Previous studies have demonstrated that patients treated with a short period of anticoagulation (4-6 weeks) have a low risk of developing recurrent DVT or PE. In addition, the specificity of CUS for distal DVT is lower than that for proximal DVT, increasing the proportion of false positive findings, making it likely that a proportion of patients diagnosed with distal DVT are treated unnecessarily, with the attendant risks of major and fatal haemorrhage.
The need for anticoagulation of patients with distal DVT to prevent recurrent DVT is therefore uncertain, however a survey of current practice suggested that most patients with this condition currently receive antithrombotic therapy. The impact of anticoagulation on initial patient symptoms, and the subsequent risk of the post-thrombotic syndrome are also unclear, and may be a possible alternative justification for antithrombotic therapy.
In this proposed multicentre, prospective, cohort study, we plan to determine if a shorter duration of anticoagulation (minimum 2 weeks) is a safe and effective treatment for isolated distal vein thrombosis.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 330 participants |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | Two Weeks of Low Molecular Weight Heparin for Distal Vein Thrombosis (TWISTER) |
Study Start Date : | November 2010 |
Estimated Primary Completion Date : | November 2013 |
Estimated Study Completion Date : | November 2014 |
- Drug: Enoxaparin
1.5mg/kg daily for 2 weeksOther Name: Clexane
- Symptomatic recurrence of venous thrombosis (DVT, non fatal and fatal pulmonary embolism) within 3 months. [ Time Frame: 3 months ]
- Asymptomatic proximal thrombus extension at 2 weeks [ Time Frame: 2 weeks ]
- Time course of symptom resolution and the proportion of patients with complete resolution at two weeks. [ Time Frame: 2 weeks ]Time course of symptom resolution including time to complete resolution of symptoms, and the proportion of patients with complete resolution at two weeks.
- All-cause mortality [ Time Frame: 3 months ]
- Post-thrombotic syndrome [ Time Frame: 6 months ]
- Predictors of recurrent or progressive DVT or new PE [ Time Frame: 3 months ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Patients aged 18 years or older with acute symptomatic provoked or unprovoked distal vein thrombosis (axial or muscular veins but not involving trifurcation or distal popliteal vein)
- Absence of symptomatic pulmonary embolism
Exclusion Criteria:
- DVT involving trifurcation or more proximal leg veins on imaging
- Prior DVT
- Active malignancy ie present at time of diagnosis, or on treatment, or treatment completed within 3 months
- Ongoing risk factors for propagation e.g. immobility (>50% of day in bed or ≥72 hours), plaster cast or non-weight bearing
- Other indication for therapeutic anticoagulation (e.g. AF)
- Active gastro-oesophageal ulceration or bleeding
- Other high risk for bleeding (e.g. recent neurosurgery, vascular retinopathy, coagulopathy)
- Platelet count <80 x 109/L
- Renal impairment (CrCl <30ml/min) • Pregnancy or lactation

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01252420
Australia, New South Wales | |
Prince of Wales Hospital | Not yet recruiting |
Sydney, New South Wales, Australia, 2031 | |
Contact: Tim Brighton, MBBs, MD +61293829013 Tim.Brighton@SESIAHS.HEALTH.NSW.GOV.AU | |
Principal Investigator: Tim Brighton, MBBs, MD | |
Australia, South Australia | |
Royal Adelaide Hospital | Not yet recruiting |
Adelaide, South Australia, Australia, 5000 | |
Contact: Simon McRae, MBBs, BMedSci +61 448882279 | |
Principal Investigator: Simon McRae, MBBs, BMedSci | |
Australia, Victoria | |
Monash Medical Centre, Southern Health | Recruiting |
Melbourne, Victoria, Australia, 3168 | |
Contact: Eileen Merriman, MBChB +61 450011998 eileen.merriman@southernhealth.org.au | |
Contact: Huyen Tran, MBBS, BClinEpi +61 408780785 huyen.tran@southernhealth.org.au | |
Principal Investigator: Huyen Tran, MBBs, MClinEp | |
Sub-Investigator: Eileen Merriman, MBChB | |
Sub-Investigator: Sanjeev Chunilal, MBChB | |
New Zealand | |
Christchurch Hospital | Not yet recruiting |
Christchurch, Canterbury, New Zealand, 8011 | |
Contact: Mark Smith, MBChB +64 3 3640640 mark.smith@cdhb.govt.nz | |
Principal Investigator: Mark Smith, MBChB |
Principal Investigator: | Huyen Tran, MBBs(Hons), MClin Epidem | Monash Medical Centre |
Responsible Party: | Huyen Tran, Monash Medical Centre, Southern Health |
ClinicalTrials.gov Identifier: | NCT01252420 History of Changes |
Other Study ID Numbers: |
DDVTANZ |
First Posted: | December 3, 2010 Key Record Dates |
Last Update Posted: | December 6, 2010 |
Last Verified: | July 2010 |
Distal Vein Thrombosis Proximal Vein Thrombosis Pulmonary Embolism Post-thrombotic syndrome Limited duration treatment |
Pulmonary Embolism Thrombosis Embolism Venous Thrombosis Embolism and Thrombosis Vascular Diseases Cardiovascular Diseases Lung Diseases |
Respiratory Tract Diseases Heparin Heparin, Low-Molecular-Weight Dalteparin Anticoagulants Fibrinolytic Agents Fibrin Modulating Agents Molecular Mechanisms of Pharmacological Action |