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A RCT to Establish the Effectiveness of Intermittent Pneumatic Compression to Prevent Post Stroke DVT (CLOTS-3)

This study has been completed.
Chief Scientist Office of the Scottish Government
National Institute for Health Research, United Kingdom
Medtronic - MITG
Information provided by (Responsible Party):
University of Edinburgh Identifier:
First received: November 11, 2008
Last updated: December 3, 2014
Last verified: December 2014

Strokes occur when blood flow to part of the brain is interrupted. Patients are often bedbound for several days or weeks although if they survive, most will make some recovery. The lack of mobility encourages blood clots to form in the legs − so called deep venous thrombosis or DVT. About 10% of patients will develop these. Pieces of this clot may break off and can be carried by the bloodstream to the lungs. These clots, called pulmonary emboli, can stop the heart and can cause patients with stroke to die suddenly. A treatment which reduces the risk of DVT after surgery is intermittent pneumatic compression (IPC). Inflatable sleeves wrapped around the legs inflate at intervals squeezing blood up the legs, increasing the blood flow, and decreasing the likelihood of clots forming − at least that is the theory!. Although this sounds uncomfortable, most people actually quite like the sensation! There have been some small randomised trials of IPC in stroke patients, particularly those with intracerebral bleeding. However, these studies although encouraging have not provided enough information to persuade clinicians to use this treatment routinely in stroke units. The proposed study will include 2000 patients who have had a stroke and who have been admitted to a stroke unit.

Patients who cannot walk independently, and who are at greatest risk of DVT will be invited to join the study. If they agree they will be randomly allocated to having routine care plus IPC or just routine care. Patient in both groups will have routine ultrasound scans on their legs to detect DVTs. The study will establish whether IPC reduces the risk of DVT. This result could improve the outcome of many thousands of patients each year.

Condition Intervention Phase
Device: Intermittent Pneumatic compression
Other: Routine care
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Randomised Trial to Establish the Effectiveness of Intermittent Pneumatic Compression to Prevent Post Stroke Deep Vein Thrombosis (DVT).

Resource links provided by NLM:

Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • Presence of definite/probable symptomatic/asymptomatic DVT in the popliteal or femoral veins (PFV) or any symptomatic DVT in the PFV within 30 days of randomisation. [ Time Frame: 30 days ]

Enrollment: 2876
Study Start Date: December 2008
Study Completion Date: March 2013
Primary Completion Date: January 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Intermittent Pneumatic Compression
SCD Express device applied with thigh length sleeves for up to 30 days
Device: Intermittent Pneumatic compression
Thigh length sleeves applied to both legs from randomization to Day 30 (Day and night) whilst sitting and lying
Other Name: Kendall SCD Express
Other: Routine care
Routine care which might include: early mobilization, adequate hydration, aspirin if ischemic stroke and graduated compression stockings according to local protocols.
Routine care
Routine care which might include: early mobilisation, adequate hydration, aspirin if ischaemic stroke and graduated compression stockings according to local protocols.
Other: Routine care
Routine care which might include: early mobilization, adequate hydration, aspirin if ischemic stroke and graduated compression stockings according to local protocols.

  Show Detailed Description


Ages Eligible for Study:   16 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Any patient admitted to hospital within 3 days of a clinical stroke fulfilling the WHO criteria.


• Who is not able to get up from a chair/ out of bed and walk to the toilet without the help of another person

Patients can be randomised from Day 0 (day of admission) to Day 3 of hospital admission. If a patient has a stroke during a hospital admission they are eligible until Day 3 from the stroke onset (Day 0). Stroke should be the most likely clinical diagnosis but a visible infarction does not have to be seen on a brain scan.

Exclusion Criteria:

  • Patients with stroke due to subarachnoid haemorrhage. These are excluded because they are generally treated in neurology/neurosurgical centres, rather than stroke units, and their care often includes coiling or clipping of aneurysms under general anaesthetic. One could therefore argue that the existing evidence support the use of IPC in surgical patients is adequate to support its routine use in this group of patients.

    • Patients who, in the opinion of the responsible clinician / nurse, are unlikely to benefit from Intermittent Pneumatic Compression - for instance those judged to have a very low risk of DVT. For instance, this would include patients who are expected to mobilise within the next day.
    • 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. These patients are likely to have a very low risk of post stroke DVT and have little potential to benefit from either the IPC or participation in the CLOTS 3 trial. However, patients who may be started on anticoagulants after the first few days for reasons other than prophylaxis against VTE e.g. secondary prevention of ischaemic stroke with atrial fibrillation are eligible for enrolment.
    • Patients with contraindications for the use of IPC. These include:

      • patients with local leg conditions in which the IPC sleeves would interfere such as dermatitis, vein ligation (immediate postoperative), gangrene, venous stasis, or recent skin graft.
      • patients with severe arteriosclerosis or other ischaemic vascular disease as indicated by absence of pedal pulses or history of definite intermittent claudication.
      • patients who have massive leg oedema or pulmonary oedema from congestive heart failure.
    • 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.
    • Patients under 16 year of age

Inclusion in another research study, including another randomised controlled trial, does not automatically exclude a patient from participating in CLOTS 3. As long as inclusion in the other study would not confound the results of CLOTS 3, co-enrolment is permissible. Also, local researchers must avoid overburdening patients. Patients should not be co-enrolled in another research study which aims to test an intervention which aims to reduce the risk of venous thromboembolism

  Contacts and Locations
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Please refer to this study by its identifier: NCT00789542

United Kingdom
University of Edinburgh
Edinburgh, Lothian, United Kingdom, EH16 4SB
Sponsors and Collaborators
University of Edinburgh
Chief Scientist Office of the Scottish Government
National Institute for Health Research, United Kingdom
Medtronic - MITG
Principal Investigator: Martin S Dennis, FRCP University of Edinburgh
  More Information

Additional Information:
Responsible Party: University of Edinburgh Identifier: NCT00789542     History of Changes
Other Study ID Numbers: 2008/W/NEU/12
ISRCTN93529999 ( Registry Identifier: ISRCTN )
Study First Received: November 11, 2008
Last Updated: December 3, 2014

Keywords provided by University of Edinburgh:
deep vein thrombosis

Additional relevant MeSH terms:
Venous Thrombosis
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases
Embolism and Thrombosis processed this record on May 25, 2017