Resistance to Aspirin and/or Clopidogrel Among Patients With PAD.
Information source: Aalborg Universitetshospital
ClinicalTrials.gov processed this data on August 20, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Intermittent Claudication
Intervention: Aspirin (Drug)
Phase: Phase 4
Status: Completed
Sponsored by: Aalborg Universitetshospital Official(s) and/or principal investigator(s): Nils Johannesen, MD, Principal Investigator, Affiliation: Department of Vascular Surgery, Aalborg Hospital
Summary
263 patients with peripheral atherosclerosis were examined to evaluate the activity of the
platelets during the standard treatment, including aspirin. A subgroup of 43 received 600 mg
of clopidogrel 2 h before platelet reactivity analysis.
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 5 years.
Clinical Details
Official title: Prevalence of Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. Prognostic Significance of Resistance to Aspirin
Study design: Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Primary outcome: Myocardial infarction, Unstable angina, Cerebral infarction, Transitory cerebral ischaemia, Percutaneous or surgical vascular intervention, Sudden deterioration of symptoms, Amputation, Death.
Detailed description:
Patients with peripheral atherosclerosis 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 ischemic events. 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, as measured by various laboratory methods. We do not know which way resistance is
best described, but it has been described that 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.
Methods:
Platelet activity is measured by the PFA-100 (Dade Behring) and by traditional turbidimetric
aggregation.
Endpoints:
Myocardial infarction, unstable angina, cerebral infarction, transitory cerebral ischaemia,
sudden deterioration of symptoms, percutaneous or surgical vascular intervention,
amputation, death.
Eligibility
Minimum age: 18 Years.
Maximum age: N/A.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Atherosclerosis of the lower limbs, defined by one of the following criteria:
Ankle-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
Locations and Contacts
Department of Vascular Surgery, Aalborg Hospital, Aalborg 9000, Denmark
Additional Information
Starting date: January 2006
Last updated: January 25, 2014
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