Effects of Low Dose Aspirin Pre-treatment on Platelet Activation Undergoing Off-pump Coronary Artery Bypass Surgery

Study Overview
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Brief Summary
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Platelet activation after off pump coronary artery bypass (OPCAB) surgery may affect thrombus formation. The purpose of this study is to assess the effects of preoperative continuation of aspirin on platelet activation after off pump coronary artery bypass surgery.

Detailed Description
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Patients undergoing OPCAB surgery will be randomized to continue preoperative aspirin or discontinue aspirin before surgery. Platelet activation can be evaluated by measuring platelet p-selectin using flowcytometry. In this study, we will compare platelet-activated markers and conventional coagulation tests.

Official Title
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Effects of Low Dose Aspirin Pre-treatment on Platelet Activation Undergoing Off-pump Coronary Artery Bypass Surgery

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Drug: aspirin continuation
* Drug: aspirin discontinuation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age : 20-80 elective OPCAB informed consent Exclusion Criteria: coagulation disorder emergency operation, re-operation co-existing valvular disease less than 6 months after cerebral vascular accident heparin induced thrombocytopenia heparin resistance menstrual phase preoperative cardiopulmonary bypass, continuous veno-veno hemofiltration, intra-aortic balloon pump application less than 12 months after myocardiac infarction less than 10 days after unstable angina less than 30 days after percutaneous coronary intervention less than 6 wks after bare metal stent insertion less than 12 months after drug eluting stent insertion

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: aspirin continuation<br>Intervention : Low-dose aspirin (< 100mg/day) is used before OPCAB surgery in the aspirin continuation group. | Drug: aspirin continuation<br>* Patients are randomized to continue aspirin before OPCAB surgery.<br>* Other names: Low-dose aspirin (< 100mg/day);|
| Experimental: aspirin discontinuation<br>Intervention: Low-dose aspirin is stopped more than 4 days before OPCAB surgery in the aspirin discontinuation group. | Drug: aspirin discontinuation<br>* Patients are randomized to discontinue aspirin more than 4 days before OPCAB surgery.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change from baseline in platelet p-selectin at 48 hours after operation | Primary outcome is expression of platelet p-selectin measured by flowcytometry 48 hours after OPCAB surgery in both groups. | after induction of anesthesia(baseline), at the time of end of operation, 24 hour after operation, 48hr after operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change from baseline in conventional coagulation tests at the time of end of operation, 24 hour after operation, and 48hr after operation | prothrombin time (international normalized ratio), activated partial thromboplastin time, fibrinogen | after induction of anesthesia(baseline), at the time of end of operation, 24 hour after operation, 48hr after operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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preoperative aspirin use, platelet activation, off pump coronary artery bypass