The Comparison of Effects Between Increased Dose of Clopidogrel and Addition of Cilostazol

Study Overview
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Brief Summary
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To compare the effect of increased dosing of clopidogrel and adding cilostazol to standard dose of clopidogrel after the insertion of drug-eluting stent in patients with clopidogrel resistance

Detailed Description
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Using dual antiplatelet agents with aspirin and clopidogrel is essential after drug-eluting stent implantation to prevent restenosis and stent thrombosis. However, variable platelet response and potential resistance to therapy have emerged with clopidogrel. Several studies showed that clopidogrel resistance is associated with increased cardiovascular events after coronary interventions. New antiplatelet therapeutic strategy of is needed in case of clopidogrel resistance. We started this study to compare the effect of double dosing of clopidogrel to 150mg per day and adding cilostazol to standard dose of clopidogrel after the insertion of drug-eluting stent in patients with clopidogrel resistance.

Official Title
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The Comparison of Effects Between Increased Dose of Clopidogrel and Addition of Cilostazol in Clopidogrel Non-Responders After Drug-Eluting Stent Implantation

Conditions
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Clopidogrel Non-Responsiveness

Intervention / Treatment
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* Drug: aspirin, clopidogrel
* Drug: aspirin, clopidogrel, cilostazol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient with clopidogrel resistance with treatment of dual antiplatelet agent, aspirin and clopidogrel, for more than 4 weeks after drug-eluting stent Clopidogrel resistance is defined as a patients with platelet inhibition less than 30% in platelet function test(VerifyNow-P2Y12 assayTM, Accumetrics, San Diego, CA, USA) Exclusion Criteria: Acute myocardial infarction within 2 weeks Unstable angina within 2 weeks History of using glycoprotein IIb/IIIa inhibitor within 1 month Cerebral infarction within 3 months Bleeding diathesis like coagulation disorder, thrombocytopenia (platelet count < 100,000/uL) history of gastrointestinal bleeding or genitourinary bleeding within 3 months needed oral anticoagulation aspirin, clopidogrel or cilostazol hypersensitivity congestive heart failure serum creatinine level >2mg/dl malignancy using cytochrome P450 inhibitor (eg, itraconazole)
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 |
| --- | --- |
| Experimental: A<br>Aspirin plus increasing clopidogrel group | Drug: aspirin, clopidogrel<br>* aspirin 100 mg plus clopidogrel 150mg qd<br>|
| Experimental: B<br>Aspirin, clopidogrel plus cilostazol group | Drug: aspirin, clopidogrel, cilostazol<br>* aspirin 100mg qd,clopidogrel 75mg qd plus cilostazol 100mg bid<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| % platelet inhibition with VeryfyNow-P2Y12 assay, platelet function test |  | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| P2Y12 reaction unit (PRU) |  | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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clopidogrel, platelets, percutaneous coronary intervention