Resistance to Aspirin and/or Clopidogrel Among Patients With PAD.
Recruitment status was Recruiting
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Purpose
1000 patients with atherosclerosis of lower limbs are examined to evaluate the activity of the platelets during the standard treatment, including aspirin. A minor group will receive clopidogrel instead of aspirin for 2 weeks.
The main hypothesis is that high platelet activity at the beginning of the study is associated with a higher risk of atherothrombosis. Follow up time is 6 years.
| Condition | Intervention | Phase |
|---|---|---|
|
Intermittent Claudication |
Drug: Clopidogrel |
Phase 4 |
| Study Type: | Interventional |
| Study Design: | Allocation: Non-Randomized Endpoint Classification: Safety/Efficacy Study Intervention Model: Single Group Assignment Masking: Open Label Primary Purpose: Diagnostic |
| Official Title: | Prevalence of Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. Prognostic Significance of Resistance to Aspirin |
- Myocardial infarction
- Unstable angina
- Cerebral infarction
- Transitory cerebral ischaemia
- Percutaneous or surgical vascular intervention
- Sudden deterioration of symptoms
- Amputation
- Death
| Estimated Enrollment: | 1000 |
| Study Start Date: | January 2006 |
Patients with atherosclerosis of the lower limbs are at high risk of atherothrombosis, mainly heart attack and stroke. The medical treatment of these patients include platelet inhibiting drugs, usually aspirin, to reduce the risk of blood clot formation. Clopidogrel is another platelet inhibiting drug, which is prescribed less often, primarily because of the high costs compared to aspirin.
Phenomena of 'resistance' to these drugs have been described by numerous investigators. Essentially resistance means that the effect of the drug described is less than expected or missing, when described by various laboratory methods. We still do not know which way resistance is best described, and we still do not know if patients who are 'resistant' to either drug are less protected against future heart attacks or strokes.
Main objectives:
- To measure the activity of platelets in these patients during aspirin treatment.
- To measure the activity of platelets in a minor population of these patients during clopidogrel treatment.
- To evaluate the prognostic significance of resistance to aspirin in these patients.
Secondary objectives:
- To describe the relation between drug resistance and the level of inflammatory markers in the blood.
Methods:
Platelet activity is measured by the PFA-100 (Dade Behring) and by traditional turbidimetric aggregation.
Patients:
Number needed is 1000.
Follow up:
6 years
Endpoints:
Myocardial infarction, unstable angina, cerebral infarction, transitory cerebral ischaemia, sudden deterioration of symptoms, percutaneous or surgical vascular intervention, amputation, death.
Eligibility| Ages Eligible for Study: | 18 Years and older |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Atherosclerosis of the lower limbs, defined by one of the following criteria: Ancle-Brachial Pressure Index (ABPI)< 0.9, intermittent claudication, ischaemic pain at rest, ischaemic ulcers or gangrene.
- Age > 18 years
- For fertile women: Use of safe contraception (intrauterine contraceptive device, the pill, hormonal skin patches, progestogen injections, progestogen implant, vaginal ring)
Exclusion Criteria:
- Allergy to either Aspirin or Clopidogrel
- Known bleeding disorder
- Platelet count < 140 mia/L or > 400 mia/L
- Intake of NSAID's, SSRI's or Dipyridamol within the preceding 14 days
- Not radically treated gastrointestinal ulceration within the last 6 month
- Greater surgical procedures performed within the last 3 month
- Severe renal disease
- Severe hepatic disease
- Breast feeding
- Pregnancy
Contacts and Locations| Contact: Esben H Madsen, MD | +01-604 221 1536 | ehmadsen@gmail.com |
| Contact: Norbert Gehr, MD | +45-99 32 29 79 | aas.u30030@nja.dk |
| Denmark | |
| Department of Vascular Surgery, Aalborg Hospital | Recruiting |
| Aalborg, Denmark, 9000 | |
| Contact: Nils Johannesen, MD | |
| Contact: Norbert Gehr, MD | |
| Principal Investigator: Nils Johannesen, MD | |
| Principal Investigator: | Nils Johannesen, MD | Department of Vascular Surgery, Aalborg Hospital |
More Information
No publications provided
| ClinicalTrials.gov Identifier: | NCT00262561 History of Changes |
| Other Study ID Numbers: | 2005-003844-68 |
| Study First Received: | December 6, 2005 |
| Last Updated: | September 27, 2006 |
| Health Authority: | Denmark: Danish Medicines Agency Denmark: The Danish National Committee on Biomedical Research Ethics |
Keywords provided by Aalborg Universityhospital:
|
Intermittent Claudication Aspirin resistance Clopidogrel resistance |
Additional relevant MeSH terms:
|
Intermittent Claudication Arteriosclerosis Arterial Occlusive Diseases Vascular Diseases Cardiovascular Diseases Signs and Symptoms Aspirin Clopidogrel Anti-Inflammatory Agents, Non-Steroidal Analgesics, Non-Narcotic Analgesics Sensory System Agents Peripheral Nervous System Agents Physiological Effects of Drugs Pharmacologic Actions |
Anti-Inflammatory Agents Therapeutic Uses Antirheumatic Agents Fibrinolytic Agents Fibrin Modulating Agents Molecular Mechanisms of Pharmacological Action Cardiovascular Agents Hematologic Agents Platelet Aggregation Inhibitors Cyclooxygenase Inhibitors Enzyme Inhibitors Antipyretics Central Nervous System Agents Purinergic P2Y Receptor Antagonists Purinergic P2 Receptor Antagonists |
ClinicalTrials.gov processed this record on May 22, 2013