Two Weeks of Low Molecular Weight Heparin for Distal Vein Thrombosis (TWISTER)
Recruitment status was: Recruiting
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Two Weeks of Low Molecular Weight Heparin for Distal Vein Thrombosis (TWISTER)|
- Symptomatic recurrence of venous thrombosis (DVT, non fatal and fatal pulmonary embolism) within 3 months. [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
- Asymptomatic proximal thrombus extension at 2 weeks [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
- Time course of symptom resolution and the proportion of patients with complete resolution at two weeks. [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]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 ] [ Designated as safety issue: Yes ]
- Post-thrombotic syndrome [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- Predictors of recurrent or progressive DVT or new PE [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
|Study Start Date:||November 2010|
|Estimated Study Completion Date:||November 2014|
|Estimated Primary Completion Date:||November 2013 (Final data collection date for primary outcome measure)|
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01252420
|Australia, New South Wales|
|Prince of Wales Hospital|
|Sydney, New South Wales, Australia, 2031|
|Australia, South Australia|
|Royal Adelaide Hospital|
|Adelaide, South Australia, Australia, 5000|
|Monash Medical Centre, Southern Health|
|Melbourne, Victoria, Australia, 3168|
|Christchurch, Canterbury, New Zealand, 8011|
|Principal Investigator:||Huyen Tran, MBBs(Hons), MClin Epidem||Monash Medical Centre|