Condition category
Circulatory System
Date applied
10/02/2009
Date assigned
21/04/2009
Last edited
12/11/2013
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Ms Julie Brittenden

ORCID ID

Contact details

Ward 36
Aberdeen Royal Infirmary
Foresterhill
Aberdeen
AB25 2ZN
United Kingdom

Additional identifiers

EudraCT number

2007-007638-21

ClinicalTrials.gov number

Protocol/serial number

Protocol 2.1

Study information

Scientific title

Is cessation of clopidogrel therapy associated with rebound of platelet activity in stable vascular disease patients? - a randomised double-blind placebo-controlled trial

Acronym

CLASP

Study hypothesis

The primary aim of this clinical trial is to identify whether there is evidence for a "rebound" effect on platelet markers associated with cessation of clopidogrel therapy. We propose to address this in patients with stable cardiovascular disease by means of a mechanistic study.

Ethics approval

North of Scotland Research Ethics Committee, approved on 07/07/2008 (ref: 08/S0801/87)

Study design

Randomised double-blind placebo-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 the contact details below to request a patient information sheet

Condition

Cardiovascular and peripheral vascular disease

Intervention

We aim to test 78 subjects in each treatment arm over a period of 2 years.

Participants will be allocated to either:
I. Clopidogrel (oral) 75 mg daily for 30 days, or
II. Placebo (oral) 75 mg daily for 30 days

On day 31, all participants will stop taking the study drugs but will continue to take their usual medications including aspirin. They will be studied for a further month, testing at 7, 14 and 28 days after stopping clopidogrel or placebo. Total duration of study = 2 months per participant.

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

Measurement of platelet activation and aggregation, before treatment, on clopidogrel/placebo, and at 7, 14 and 28 days after cessation of clopidogrel/placebo.

Secondary outcome measures

The following inflammatory and procoagulant markers will be assessed before treatment, on clopidogrel/placebo, and at 7, 14 and 28 days after cessation of clopidogrel/placebo:
1. High-sensitivity C-reactive protein (hs-CRP)
2. D-Dimer
3. Soluble CD40 (sCD40) ligand
4. Soluble P-selectin (sP-selectin)

While the primary aim of this study is not to measure clinical outcome, such data will be collected in order to inform a later multi-centre clinical outcome study.

Overall trial start date

26/11/2008

Overall trial end date

31/07/2011

Reason abandoned

Eligibility

Participant inclusion criteria

1. Both males and females, age 30-80 years
2. Evidence of chronic atherosclerotic disease - stable coronary heart disease or peripheral arterial disease
3. Already receiving standard secondary prevention therapy for cardiovascular disease, including aspirin therapy and a statin
4. Able to give informed consent

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

156

Participant exclusion criteria

1. Known allergy to clopidogrel
2. Contraindications to clopidogrel as listed in the Summary of Product
3. Characteristics for clopidogrel (i.e Hypersensitivity to the active substance or to any of the excipients of the medicinal product, severe liver impairment, active pathological bleeding such as peptic ulcer or intracranial haemorrhage, breast feeding)
Also:
4. History of thrombocytopenia, neutropenia or haematological malignancy
5. Bleeding diathesis
6. Abnormal renal or hepatic function
7. Transfusion of whole blood cells within 14 days prior to randomisation
8. Known or suspected drug or alcohol abuse
9. Clinical symptoms of heart failure
10. Women of child-bearing potential
11. Taking anticoagulant or antiplatelet drugs other than aspirin
12. Participation in another clinical trial of a medicinal product (CTIMP) within preceding 3 months

Recruitment start date

26/11/2008

Recruitment end date

31/07/2011

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Ward 36
Aberdeen
AB25 2ZN
United Kingdom

Sponsor information

Organisation

Grampian Health Board and University of Aberdeen (UK)

Sponsor details

Research and Development
Foresterhill Annex
Foresterhill
Aberdeen
AB25 2ZN
United Kingdom
mmd175@abdn.ac.uk

Sponsor type

Government

Website

http://www.nhsgrampian.org

Funders

Funder type

Charity

Funder name

Heart Research UK (UK) (ref: RG2555/08/10) - main funder

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

UK Clinical Research Collaboration (UKCRC) via the Chief Scientist Office (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

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

Results - basic reporting

Publication summary

2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24211510

Publication citations

  1. Results

    Ford I, Scott NW, Herd V, Mitchell LR, Williams DJ, Brittenden J, A randomized controlled trial of platelet activity before and after cessation of clopidogrel therapy in patients with stable cardiovascular disease., J. Am. Coll. Cardiol., 2014, 63, 3, 233-239, doi: 10.1016/j.jacc.2013.10.018.

Additional files

Editorial Notes