Resistance to Antithrombotic Therapy

Study Overview
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Brief Summary
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Clopidogrel plays a pivotal role in the antithrombotic regimen after percutaneous intervention with stent implantation. However, response to clopidogrel shows a wide interindividual variability and a high on-treatment residual ADP-inducible platelet reactivity has already been associated with an increased risk for adverse events after coronary stenting. In the present study, platelet reactivity will be determined by 6 different platelet function tests in patients on dual antiplatelet therapy after angioplasty and stenting for peripheral, coronary and carotid artery disease. One hundred patients showing high on-treatment residual ADP-inducible platelet reactivity in 2 or more tests will be randomized to receive either 75mg or 150mg of daily clopidogrel in addition to aspirin for 3 months. The aim of the present study is to investigate the effects of intensified antithrombotic therapy (150mg clopidogrel + 100mg aspirin daily) versus standard antithrombotic therapy (75mg clopidogrel + 100mg aspirin daily) in patients with decreased clopidogrel-mediated platelet inhibition after percutaneous intervention with stent implantation.

Official Title
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Resistance to Antithrombotic Therapy in Patients Undergoing Angioplasty and Stenting for Cardiovascular Disease - Vienna REACT

Conditions
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Atherosclerosis, Angioplasty

Intervention / Treatment
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* Drug: aspirin
* Drug: clopidogrel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: written informed consent angioplasty and stenting for peripheral, coronary or carotid artery disease Exclusion Criteria: known aspirin or clopidogrel intolerance therapy with vitamin K antagonists (warfarin, phenprocoumon, acenocoumarol) treatment with ticlopidine, dipyridamol or nonsteroidal antiinflammatory drugs family or personal history of bleeding disorders malignant paraproteinemias myeloproliferative disorders heparin-induced thrombocytopenia severe hepatic failure known qualitative defects in thrombocyte function major surgical procedure within one week before enrollment platelet count < 100.000 or > 450.000/µl hemoglobin < 8 g/dl

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>75 mg clopidogrel + 100 mg aspirin | Drug: aspirin<br>* 100 mg aspirin<br>Drug: clopidogrel<br>* 75 mg (Arm 1) and 150 mg (Arm 2)<br>|
| Active Comparator: 2<br>150 mg clopidogrel + 100 mg aspirin | Drug: aspirin<br>* 100 mg aspirin<br>Drug: clopidogrel<br>* 75 mg (Arm 1) and 150 mg (Arm 2)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurence of major adverse cardiovascular events (MACE) |  | 3 months | 
| Occurence of major adverse cardiovascular events (MACE) |  | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Clopidogrel, Aspirin, Antithrombotic therapy, Platelet function testing