Evaluation of the Biological Response to Clopidogrel in Patients With Ischemic Stroke (AAPIX)
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT01955642 |
Recruitment Status
:
Completed
First Posted
: October 7, 2013
Last Update Posted
: December 31, 2015
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Ischemic stroke (AIC) is the leading cause of non-traumatic disability in adults, the second leading cause of dementia and the third leading cause of death in France.
Clopidogrel is one of the recommended first line in the secondary prevention of AIC non cardioembolic origin. However recurrences occur in approximately 9% of patients receiving clopidogrel. Some studies in patients with coronary artery disease have made the connection between these treatment failures and non-biological response to clopidogrel. This non-biological response is found for approximately 30% to 50% of patients. Several mechanisms may explain this non-response. The most accepted mechanism is pharmacokinetic. Indeed, clopidogrel is a prodrug that requires intestinal absorption by P-glycoprotein (PGP) and a transformation by hepatic cytochrome into active metabolites. The genetic polymorphism of proteins involved in these two steps explain the low plasma concentration of active metabolites and thus the low efficacy of clopidogrel in some patients.
A new pharmacodynamic hypothesis suggests the involvement of platelet alpha 2-adrenergic receptors. The activation of these receptors potentiates signaling pathway P2Y12 receptor (channel inhibited by clopidogrel) and helps reduce platelet aggregation inhibiting response to clopidogrel.
Condition or disease | Intervention/treatment |
---|---|
Brain Ischemia Ischemic Attack | Drug: Clopidogrel |
Study Type : | Observational |
Actual Enrollment : | 91 participants |
Observational Model: | Case-Only |
Time Perspective: | Prospective |
Official Title: | Evaluation of the Biological Response to Clopidogrel in Patients With Ischemic Stroke : Role of Platelet alpha2-adrenergic Receptors |
Study Start Date : | September 2013 |
Actual Primary Completion Date : | December 2015 |
Actual Study Completion Date : | December 2015 |

Group/Cohort | Intervention/treatment |
---|---|
AVC
Patients with non-cardioembolic AIC requiring initiation of treatment with clopidogrel as usual indications
|
Drug: Clopidogrel
75 mg milligrams per days of PLAVIX
Other Name: PLAVIX(R)
|
- adrenergic component of the platelet response [ Time Frame: 5 days after taking clopidogrel ]adrenergic component of the platelet response is estimated by the difference between the maximum percentage of platelet aggregation by light transmission aggregometry (LTA) with the addition of ADP(adenosine diphosphate) + ADP versus selective agonist (epinephrine)
- VASP-CMF [ Time Frame: After 5 days taking clopidogrel ]Platelet reactivity index (PRI) by VASP CMF (flow cytometry) method
- ELISA VASP [ Time Frame: After 5 days taking clopidogrel ]Platelet reactivity index (PRI-ELISA) using ELISA VASP
- active metabolite of clopidogrel [ Time Frame: After 5 days taking clopidogrel ]Rate of residual plasma active metabolite of clopidogrel (R-130964)
- Genotyping of MDR-1 and P450 2C19 [ Time Frame: After 5 days taking clopidogrel ]Genotyping of MDR-1 and P450 2C19
Biospecimen Retention: Samples With DNA

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Senior) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Consent signed
- Patients with non-cardioembolic AIC requiring initiation of treatment with clopidogrel as usual indications
- normal standard biological tests
Exclusion Criteria:
- Need to continue aspirin therapy
- Patients with a recurrence of clopidogrel AIC
- Patient already tacking clopidogrel
- Drugs interfering with the adrenergic system alpha blockers, alpha 2 receptor agonists (alpha-methyldopa) and alpha2 receptor inhibitors (Mianserin, Mirtazapine, yohimbine)
- Contra indication of clopidogrel and / or any of its excipients

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01955642
France | |
CHU de Saint-Etienne | |
Saint-etienne, France, 42000 |
Principal Investigator: | Jerome VARVAT, MD | CHU de Saint-Etienne |
Responsible Party: | Centre Hospitalier Universitaire de Saint Etienne |
ClinicalTrials.gov Identifier: | NCT01955642 History of Changes |
Other Study ID Numbers: |
1208094 2013-000313-20 ( EudraCT Number ) |
First Posted: | October 7, 2013 Key Record Dates |
Last Update Posted: | December 31, 2015 |
Last Verified: | December 2015 |
Keywords provided by Centre Hospitalier Universitaire de Saint Etienne:
Clopidogrel Brain Ischemia Ischemic attack Biological response to clopidogrel |
Additional relevant MeSH terms:
Ischemia Brain Ischemia Pathologic Processes Cerebrovascular Disorders Brain Diseases Central Nervous System Diseases Nervous System Diseases Vascular Diseases Cardiovascular Diseases Clopidogrel Ticlopidine Platelet Aggregation Inhibitors |
Purinergic P2Y Receptor Antagonists Purinergic P2 Receptor Antagonists Purinergic Antagonists Purinergic Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Physiological Effects of Drugs Fibrinolytic Agents Fibrin Modulating Agents Cytochrome P-450 CYP2C19 Inhibitors Cytochrome P-450 Enzyme Inhibitors Enzyme Inhibitors |