Contact information
Type
Scientific
Primary contact
Prof Kevin Mackway-Jones
ORCID ID
Contact details
Emergency Department
Manchester Royal Infirmary
Oxford Road
Manchester
M13 9WL
United Kingdom
+44 (0)1612 766781
kevin.c.mackway-jones@manchester.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
781875
Study information
Scientific title
The Anticoagulation of Calf Thrombosis (ACT) Study: a randomised controlled trial comparing standardised anticoagulation versus conservative therapy in the treatment of below knee deep vein thrombosis
Acronym
ACT
Study hypothesis
The treatment of a blood clot in the leg below the level of the knee is a long debated topic. There is ongoing discussion about whether to treat this condition actively with drugs to thin the blood (anticoagulants) or to simply 'watch and wait'. Both approaches are utilised at different hospitals in the North West.
Some hospitals 'watch and wait' only. They scan the leg 1 week after presentation, treating only if the clot gets bigger. Several research studies suggest this is as safe an approach as treating the clot. It also avoids exposing patients to the inherent risks of blood thinning drugs.
Other hospitals worry about the chance of the clot moving up the leg and rarely into the lungs. They practice treating all patients with anticoagulants to reduce these risks as much as possible. This also means that patients do not have to come back in a weeks time for another scan. Although some risk may be reduced by this approach, there is a potential for anticoagulant drugs to cause harm.
This research is trying to find out which approach is safest for patients. To find this out, we propose to randomly allocate patients with below knee blood clots to receive conservative treatment, (stocking supports and simple painkillers), or conservative treatment and
anticoagulation. All patients will receive serial leg scans and be followed closely. Short-term assessment and long term follow up will occur.
If the trial shows a benefit from treating below knee clots, this will have a major impact on those hospitals which only scan above the knee, as many currently do. If the trial shows no benefit to treating the clots, many patients will be able to avoid the dangers of anticoagulation and further risk.
This feasibility trial will look to establish the percentage of recruitable patients from available cohort and feasibility of maintaining treatment allocation for three months.
Ethics approval
The North West 7 Research Ethics Committee (REC) - GM Central approved on the 15th of November 2010 subject to a complete response to request for further information (ref: 10/H1008/97)
Study design
Prospective open label randomised controlled trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Hospitals
Trial type
Treatment
Patient information sheet
Not available in web format, please use contact details below to request a patient information sheet
Condition
Calf thrombosis/below knee DVT
Intervention
Patients will be randomised to one of the following treatment groups
1. Group A: conservative treatment (TED stockings and simple analgaesia) and full-dose anticoagulation, initiated with Low Molecular Weight Heparin (LMWH) (dalteparin, dosage based on weight) then converted to oral anticoagulation with warfarin for a duration of 3 months total. Warfarin dosing to be based on International Normalized Ratio (INR) blood clotting measurements aiming for a target range of 2-3.
2. Group B: conservative treatment only
All patients will have vascular ultrasound scans at 7 days and 21 days to look for propagation or clot development, along with clinical review. All patients will be clinically followed for the three month duration of treatment. All patients will also be reviewed at two years regarding assessment for post-thrombotic leg syndrome.
Intervention type
Other
Phase
Phase IV
Drug names
Primary outcome measure
Combined incidence of thrombus propagation above knee or development of pulmonary embolism during the 3 months randomisation period
Secondary outcome measures
1. Incidence of major and minor bleeding episodes
2. Incidence of post thrombotic leg syndrome at 2 years using validated screening tool
3. Incidence of DVT recurrence at 2 years
Overall trial start date
01/01/2011
Overall trial end date
01/08/2012
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. All ambulatory outpatients presenting to Manchester Royal Infirmary Emergency department diagnosed with below knee calf vein thrombosis by vascular ultrasound scan (USS)
2. Able to give informed consent
3. Aged 16-90
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
100 for primary feasibility
Participant exclusion criteria
1. Hospitalised patients
2. Patients on long-term anticoagulation
3. Associated proximal DVT or confirmed PE
4. Contraindication to anticoagulation (active bleeding, recent haemorrhagic CVA or upper GI bleed)
5. Other indication for immediate warfarinisation as per BSH guidelines: Prior confirmed and treated above knee DVT/PE, antiphospholipid syndrome, symptomatic inherited thrombophilia
6. Pregnancy
7. Chronic non propagating thrombus seen on prior USS
8. Previous enrolment to the ACT study and achievement of the primary outcome
Recruitment start date
01/01/2011
Recruitment end date
01/08/2012
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Emergency Department
Manchester
M13 9WL
United Kingdom
Sponsor information
Organisation
Central Manchester NHS Foundation Trust (UK)
Sponsor details
c/o Lynne Webster
Research and Development
1st Floor Postgraduate Centre
Manchester Royal Infirmary
Oxford Road
Manchester
M13 9WL
United Kingdom
+44 (0)1612 763565
lynne.webster@cmft.nhs.uk
Sponsor type
Hospital/treatment centre
Website
Funders
Funder type
University/education
Funder name
College of Emergency Medicine (UK)
Alternative name(s)
CEM
Funding Body Type
private sector organisation
Funding Body Subtype
academic
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
2012 protocol in: http://www.ncbi.nlm.nih.gov/pubmed/22472294
2014 results in: http://www.ncbi.nlm.nih.gov/pubmed/25010443
Publication citations
-
Protocol
Horner D, Hogg K, Body R, Nash MJ, Mackway-Jones K, The Anticoagulation of Calf Thrombosis (ACT) project: study protocol for a randomized controlled trial., Trials, 2012, 13, 31, doi: 10.1186/1745-6215-13-31.
-
Results
Horner D, Hogg K, Body R, Nash MJ, Baglin T, Mackway-Jones K, The Anticoagulation of Calf Thrombosis (ACT) project: results from the randomized controlled external pilot trial., Chest, 2014, doi: 10.1378/chest.14-0235.