A randomised trial to establish the effectiveness of intermittent pneumatic compression sleeves (applied to the legs) to prevent post stroke deep vein thrombosis (DVT)

ISRCTN ISRCTN93529999
DOI https://doi.org/10.1186/ISRCTN93529999
ClinicalTrials.gov number NCT00789542
Secondary identifying numbers HTA 08/14/03; Version 2
Submission date
26/08/2008
Registration date
09/10/2008
Last edited
30/09/2015
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims.
Patients who are immobile due to illness are at increased risk of developing blood clots in the veins of their legs. These are called deep vein thrombosis or DVT for short. Although patients may experience pain, swelling and redness of their leg associated with these clots, they may not have any symptoms. However, even if they have no symptoms these DVTs can be very dangerous. The clot may break into pieces and be carried to the lungs and heart (called pulmonary embolism) where they can cause the heart to stop. Some patients die suddenly from pulmonary embolism. Patients who are admitted to hospital with a stroke are at particular risk since they are often immobile. Although blood thinning drugs can help reduce the risk of the clots, their benefits are offset by an increased risk of bleeding complications. The CLOTS 1 trial showed that graduated compression stockings (like fight socks) do not reduce the risk of DVT in stroke patients. The CLOTS 3 trial is testing whether Intermittent Pneumatic Compression (called IPC for short) reduces the risk of DVT, pulmonary embolism and death. IPC involves wrapping inflatable sleeves around the legs. These contain air sacs which are inflated, first around the calf, and then the thigh. The squeezing of the leg increases blood flow in the veins and this may reduce the risk of clots forming. The sleeves are attached to an electric air pump at the bedside via tubing. IPC has been shown to reduce the risk of DVT in patients undergoing surgery, but not in patients with other medical conditions including stroke. The aim of the CLOTS 3 trial is to test whether IPC reduces the risk of DVT in patients who are admitted to hospital with a stroke and who are immobile.

Who can participate?
Patients over 16 years old, who are admitted to one of the 105 participating hospitals in the UK, and who have had a stroke and are immobile can be recruited by their doctors and nurses into the trial.

What does the study involve?
Once the patient, or someone close to them, has consented to participating in the trial, the patient's details are entered into a computer. The patient is randomly allocated to wear the IPC for up to 30 days, or not. All recruited patients, whether they wear the IPC or not then have ultrasound scans of their legs at one week and four weeks to detect any DVT. The patients are followed up for six months to establish how well they recover. All other treatments are the same in the patients wearing IPC or not.

What are the possible benefits and risks of participating?
The benefits of participating are that the patients have scans which may detect a clot. These can then be treated with anticoagulants. This may reduce the risk of serious complications. Also, patients in the trial benefit from routine follow up at six months which can identify other post stroke problems such as depression and pain. Apart from the inconvenience of participating in the trial the risks are probably small. In theory the IPC could cause skins problems and the tubing might trip the patient up if they try to walk resulting in injuries.

Where is the study run from?
The study is run by a team in the University of Edinburgh, based at the Western General Hospital in Edinburgh, Scotland.

When is the study starting and how long is it expected to run for?
The first patient of the 2876 patients recruited was recruited in December 2008 and the last in September 2012. The follow up was completed in March 2013, and the results will be available in May 2013.

Who is funding the study?
The main funder was the National Institute of Health Research (NIHR) Health Technology Assessment (HTA) board of the UK. The Chief Scientist Office of the Scottish Government funded the start up phase. Covidien supplied the centres with their IPC sleeves and pumps (Kendallâ„¢ SCD Express Sequential Compression System). Staff funded by the UK stroke research network ran the trial in the 105 UK centres.

Who is the main contact?
Prof Martin Dennis, Professor of stroke medicine, University of Edinburgh.

Study website

Contact information

Prof Martin Dennis
Scientific

Bramwell Dott Building
Division of Clinical Neurosciences
Western General Hospital
Crere Road
Edinburgh
EH4 2XU
United Kingdom

Study information

Study designMulti-centre randomised controlled trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typePrevention
Participant information sheet Information for patients may be found at http://www.dcn.ed.ac.uk/clots/clots_patient_area/index.html
Scientific titleA randomised trial to establish the effectiveness of intermittent pneumatic compression to prevent post stroke deep vein thrombosis (DVT)
Study acronymCLOTS-3
Study hypothesisDoes early and routine application of intermittent pneumatic compression (IPC) in addition to routine care reduce the risk of above knee deep vein thrombosis (DVT) in the weeks following an acute stroke?

More details can be found at http://www.nets.nihr.ac.uk/projects/hta/081403
Protocol at http://www.nets.nihr.ac.uk/__data/assets/pdf_file/0005/52394/PRO-08-14-03.pdf

Please note that as of 20/05/2010 this record has been updated to reflect changes in the trial protocol from Version 1 to Version 2. Point 3 of the original exclusion criteria has been removed, this and all updates can be found in the relevant field under the above update date. Please also note that this trial has been extended. The overall trial end date has been changed from 30/04/2013 to 30/09/2014.

On 20/03/2013 the overall trial end date was updated from 30/09/2014 to 31/03/2013.
Ethics approval(s)1. MREC Scotland, 25/09/2008, ref: 08/MRE00/73
2. Additional approval for England and Wales obtained on 26/08/2008, ref: 08/H0906/137
ConditionStroke
InterventionRoutine care vs routine care plus IPC sleeves. If allocated to the intervention group, thigh length IPC sleeves should be applied to both legs for 30 days.
Intervention typeOther
Primary outcome measurePresence of definite or probable symptomatic or asymptomatic DVT in the popliteal or femoral veins detected on a screening Compression Doppler ultrasound scan or any symptomatic DVT in the popliteal or femoral veins confirmed on Compression Doppler ultrasound, contrast venography or magnetic resonance imaging (MRI) direct thrombus imaging within 30 days of randomisation.
Secondary outcome measuresIn hospital:
1. Death within 30 days
2. Presence of definite or probable DVT in the popliteal or femoral veins detected on a screening Compression Doppler ultrasound scan which had not been suspected clinically before the scan (see below)
3. Definite (i.e. excluding probable DVTs) symptomatic or asymptomatic DVT in the popliteal or femoral veins detected on either a Compression Doppler ultrasound scan, contrast venography or MRI direct thrombus imaging within 30 days of randomisation
4. Any definite or probable symptomatic or asymptomatic DVT (i.e. including DVTs which only involve the calf veins)
5. Confirmed fatal or non-fatal pulmonary embolism (PE)
6. Adherence to allocated treatment

At 6 months:
7. Death from any cause
8. Any confirmed symptomatic or asymptomatic DVT or PE occurring between randomisation and final follow up
9. Any symptomatic DVT or PE occurring between randomisation and final follow up
10. Place of residence
11. Post DVT syndrome
12. Disability (modified Rankin)
13. Health related quality of life (EuroQol). The later effects of DVT/PE (e.g., breathlessness, leg pain or swelling, poor stroke recovery) or the adverse events related to IPC (falls with injury, fractures, skin ulceration, amputation, loss of mobility) may be diverse, so it seems sensible to include a measure of overall health related quality of life.
Overall study start date01/12/2008
Overall study end date31/03/2013

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants2,000
Participant inclusion criteria1. Patients (both males and females) who were admitted to hospital within 3 days of a clinical stroke fulfilling the World Health Organization (WHO) criteria
2. Those who are not able to get up from a chair/out of bed and walk to the toilet without the help of another person
Participant exclusion criteriaCurrent information as of 20/05/2010:
1. Patients with stroke due to subarachnoid haemorrhage
2. Patients who, in the opinion of the responsible clinician/nurse, are unlikely to benefit from IPC
3. Patients with contraindications for the use of IPC
4. Patients who already have swelling or other signs of an existing DVT. Such patients may be recruited once a DVT has been excluded by normal D Dimers or Compression Doppler ultrasound.
5. Patients under 16 years of age

Initial information at time of registration:
1. Patients with stroke due to subarachnoid haemorrhage
2. Patients who, in the opinion of the responsible clinician/nurse, are unlikely to benefit from IPC
3. Patients who are anticoagulated (taking warfarin, unfractionated heparin, low molecular weight heparin or direct thrombin inhibitors) at the time of enrolment in whom it is planned to continue the anticoagulation throughout the first week or two after the stroke
4. Patients with contraindications for the use of IPC
5. Patients who already have swelling or other signs of an existing DVT. Such patients may be recruited once a DVT has been excluded by normal D Dimers or Compression Doppler ultrasound.
6. Patients under 16 years of age
Recruitment start date01/12/2008
Recruitment end date01/09/2012

Locations

Countries of recruitment

  • Scotland
  • United Kingdom

Study participating centres

Western General Hospital
Edinburgh
EH4 2XU
United Kingdom
105 participating hospitals
-
United Kingdom

Sponsor information

University of Edinburgh (UK)
University/education

Edinburgh Clinical Trials Unit
Queens Medical Research Institute
47 Little France Crescent
Edinburgh
EH16 4TJ
Scotland
United Kingdom

Website http://www.ed.ac.uk
Lothian NHS Board (UK)
Hospital/treatment centre

Deaconess House
148 Pleasance
Edinburgh
EH8 9RS
Scotland
United Kingdom

Website http://www.nhslothian.scot.nhs.uk
University of Edinburgh
Not defined

Funders

Funder type

Government

Chief Scientist Office (UK) (ref: CZG\2\378)
Government organisation / Local government
Alternative name(s)
CSO
Location
United Kingdom
Added 20/05/10:

No information available

NIHR Health Technology Assessment Programme - HTA (UK) (ref: 08/14/03)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article protocol 08/03/2012 Yes No
Statistical Analysis Plan statistical analysis plan 06/03/2013 No No
Results article results 10/08/2013 Yes No
Results article results 01/09/2015 Yes No