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 measure
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 (if study stopped)
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
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
Basic results (scientific)
Publication list
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24211510
Publication citations
-
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.