Extrait

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

Critère d'inclusion

• Topic: Cardiovascular; Subtopic: Cardiovascular (all Subtopics); Disease: Cardiovascular

Liens

• isrctn
• ictrp