ISRCTN ISRCTN06023644
DOI https://doi.org/10.1186/ISRCTN06023644
Secondary identifying numbers 4069
Submission date
23/04/2010
Registration date
23/04/2010
Last edited
23/09/2016
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 of protocol

Background and study aims (to set the scene)
Despite many improvements in the treatment of heart disease and stroke, these conditions remain very common in Western countries, including the UK. One of the main treatments that is used to prevent heart attacks and strokes, in people who are at risk of these, including patients who have previously suffered heart disease or strokes, is aspirin. Aspirin works by inhibiting the activity of certain blood cells, called platelets, which play a role in forming clots in the arteries. However, despite taking aspirin, a number of patients who have previously had heart attacks or strokes experience another such event. These patients have been labelled as ‘aspirin resistant’, and much research is currently going on to try and find out why aspirin resistance occurs. Recently, several lines of evidence suggest that aspirin resistance may in fact be genetically determined, at least in part, although the genes concerned are presently not clear. This study aims to determine, both in healthy people and in patients with a history of heart disease or stroke, whether variations in certain genes that can affect the functioning of blood platelets may indeed give rise to aspirin resistance.

Who can participate?
Healthy adults aged at least 18.

What does the study involve?
Participants attend the study centre and, after a period of lying down resting, are asked to give a 100 ml blood sample (the equivalent of about 6 tablespoonfuls) from a vein. These samples are used for routine blood tests, to measure the functioning of the blood platelets in the laboratory and to study the DNA (genetic material) of some of the genes that may be important in controlling how platelets respond to aspirin. Participants are also be asked to give a urine sample at this visit, which is analysed to give another measure of how activated platelets are in the bloodstream. Some of the blood is frozen, for subsequent genetic analysis. Subjects are given aspirin 300mg daily for 4 weeks, at the end of which time they re−attend once again under the same conditions as above, for further blood (80 ml blood) and urine testing.

What are the possible benefits and risks of participating?
There are no specific benefit to taking part in the study, and participants treatment will not be affected in any way either by their participation / non-participation or by the results that obtained from them. However, the information that is obtained from this study may help to to treat future patients with (or at risk of) heart disease or stroke better. Participants may experience slight discomfort in the arm following insertion of a needle for taking blood. Aspirin treatment may give rise to bleeding or bruising, both at the site of blood taking and elsewhere, because aspirin works by thinning the blood slightly. Any such bruising or bleeding is usually minor, but may be more severe if the participant has a reason to bleed easily, for example recent surgery or a blood clotting disorder. Overall, the risk of increased bruising and bleeding (minor and major combined) is approximately 1 in 100. Additionally, aspirin can cause stomach irritation or even ulcers; however, participants who have a history of this will be excluded to minimize the risk of this happening.

Where is the study run from?
King's College London

When is the study starting and how long is it expected to run for?
January 2007 to December 2008

Who is funding the study?
Biotechnology and Biological Science Research Council

Who is the main contact?
Professor Albert Ferro

Contact information

Prof Albert Ferro
Scientific

King's College London
3.07 Franklin-Wilkins Building
150 Stamford Street
London
SE1 9NH
United Kingdom

Study information

Study designNon-randomised interventional treatment trial
Primary study designInterventional
Secondary study designNon randomised study
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleAn investigation into the genes underlying the clinical syndrome of aspirin resistance: a non-randomised interventional treatment trial
Study objectives1. What is the prevalence of true aspirin resistance in a healthy population?
2. Can a genetic basis be identified for this?
Ethics approval(s)Riverside Research Ethics Committee approved in February 2007, ref: 07/Q0401/1
Health condition(s) or problem(s) studiedTopic: Cardiovascular; Subtopic: Cardiovascular (all Subtopics); Disease: Cardiovascular
InterventionAs of 01/08/2016:
Subjects will attend clinic following an overnight fast, and having abstained from tobacco, caffeine−containing drinks and alcohol for at least 12 hours. 100 ml blood will be taken from an antecubital
vein using a 19G needle, for both genotyping and platelet phenotyping. These baseline bloods will also be sent for routine haematology and biochemistry screening (full blood count, renal function, liver profile, lipid profile, glucose, HbA1c, homocysteine, hsCRP). A urine sample will also be taken for measurement of 11−dehydrothromboxane B2 and creatinine (the ratio of 11−dehydrothromboxane B2 to creatinine in urine is a well validated index of platelet activation). One week later, subjects will re−attend under the same conditions as above, for further venesection (80 ml blood) and repeat platelet phenotyping (we will not need to repeat the DNA analyses, haematology or biochemistry testing on visit 2), in order to establish a stable baseline for platelet function studies. Another urine sample will be taken for measurement of 11−dehydrothromboxane B2 to creatinine ratio. Subjects will then be given aspirin 300mg daily for 4 weeks, at the end of which time they will re−attend once again under the same conditions as above, for further venesection (80 ml blood) and repeat platelet phenotyping and urinary 11−dehydrothromboxane B2 to creatinine ratio measurement.

Initial:
Aspirin 300 mg daily adminstered for 1 month. Follow up length: 1 month.
Intervention typeDrug
Pharmaceutical study type(s)
PhasePhase IV
Drug / device / biological / vaccine name(s)Aspirin
Primary outcome measurePresence of aspirin resistance at 1 month
Secondary outcome measuresPresence/absence of genetic polymorphisms in a number of candidate genes possibly related to aspirin at 1 month
Overall study start date01/01/2007
Completion date31/12/2008

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexNot Specified
Target number of participantsPlanned Sample Size: 100
Key inclusion criteriaMale or female aged 18 or more
Key exclusion criteria1. Significant co-morbidity
2. Current regular therapy with any drug
3. Ingestion of aspirin, other non-steroidal anti-inflammatory drug, or other anti-platelet agent within the previous 30 days
4. Previous reaction to aspirin or other anti-platelet drug
5. History of dyspepsia or peptic ulceration
6. Pregnancy or female currently trying to conceive. Females of reproductive age wishing to take part will be asked to undergo a pregnancy test prior to inclusion, and will participate only if the test is negative.
Date of first enrolment01/01/2007
Date of final enrolment31/12/2008

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

King's College London
London
SE1 9NH
United Kingdom

Sponsor information

Kings College London (UK)
University/education

c/o Keith Brennan
1.8 Hodgkin Building
Guy's Campus
London
SE1 1UL
England
United Kingdom

Website http://www.kcl.ac.uk/
ROR logo "ROR" https://ror.org/0220mzb33

Funders

Funder type

Research council

Biotechnology and Biological Science Research Council (BBSRC) (UK)

No information available

Heart Research UK (UK)
Private sector organisation / Other non-profit organizations
Location
United Kingdom

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?
Results article results: 01/08/2014 Yes No

Editorial Notes

23/09/2016: Added plain English summary
01/08/2016: Added information to interventions and added publication
12/07/2016: No publications found, verifying study status with principal investigator