Antiplatelet Effect of Low Doses of Aspirin Taken Every 12 Hours in Patients Undergoing Coronary Artery Bypass Graft and/or Aortic Valve Surgery

Study Overview
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Brief Summary
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This study is a randomized open label study that implies the administration of asprin according to three different regimens. The aims of the study are: to establish whether coronary artery bypass surgery and / or aortic valve replacement surgery with bioprostheses is associated with changes in the rate of platelet regeneration that can reduce the effectiveness of aspirin administered at a dose of 100mg/die in terms of inhibition of platelet biosynthesis of thromboxane A2. to determine whether these patients need a different (shorter) interval of administration in order to completely and permanently inhibit the platelet COX-1. The endpoints of this study are: - To evaluate the changes in the levels of TXB2 and 12-HETE in serum at 12 and 24 hours after administration of aspirin and the changes in the levels of 11-dehydro TXB2 urinary 8-iso-PGF2 alpha urinary, 2-3 dinor-6-chetoPGF1 alpha, Verify-NOW Aspirin, platelets crosslinked at 12 and 24 hours after administration of aspirin

Conditions
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Coronary Arteriosclerosis

Intervention / Treatment
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* Drug: Aspirin
* Drug: Aspirin
* Drug: Aspirin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: informed consent of the study signed coronary artery bypass graft and / or aortic valve replacement surgery with bioprostheses age between 55 and 80 ejection fraction > 30%. Exclusion Criteria: excessive bleeding (> 1000mL / 6 h) or the need of re operation for bleeding perioperative myocardial infarction stroke or renal failure requiring dialysis and need waiting for post-operative anticoagulation patients undergoing coronary artery bypass grafting procedure as a consequence of failed percutaneous coronary intervention patients undergoing off-pump coronary artery bypass graft overt kidney or liver disease therapies that influence the coagulation fertile women

Ages Eligible for Study
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Minimum Age: 55 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Aspirin 100<br> | Drug: Aspirin<br>* single-dose aspirin in 100 mg 1 tablet every 24 hours<br>|
| Active Comparator: Aspirin 200<br> | Drug: Aspirin<br>* single-dose aspirin 200 mg 1 tablet every 24 hours<br>|
| Active Comparator: Aspirin 100 x 2<br> | Drug: Aspirin<br>* double-dose aspirin 100 mg 1 tablet every 12 hours<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in the levels of TXB2 in serum at 12 and 24 hours after administration of aspirin |  | one year | 
| change in the levels of 12-HETE in serum at 12 and 24 hours after administration of aspirin |  | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in the levels of 11-dehydro TXB2 urinary at 12 and 24 hours after administration of aspirin |  | one year | 
| change in the levels of 8-iso-PGF2 alpha urinary at 12 and 24 hours after administration of aspirin |  | one year | 
| change in the levels of 2-3 dinor-6-chetoPGF1 alpha at 12 and 24 hours after administration of aspirin |  | one year | 
| change in the levels of Verify-NOW Aspirin, platelets crosslinked at 12 and 24 hours after administration of aspirin |  | one year |