ThrombElastoGraphic Haemostatic Status and Antiplatelet Therapy After Coronary Artery Bypass Graft Surgery

Study Overview
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Brief Summary
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The purpose of this study is to determine whether adding clopidogrel to aspirin after coronary bypass operation (CABG) improves graft patency, in patients that have preoperatively increased platelet activity(hypercoagulable) and therefore greater risk of graft occlusion( thrombosis).

Detailed Description
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Graft patency after CABG is reported to 80-90% worldwide 1 year following surgery. In the immediate period after surgery, and the following month, graft occlusion mainly occurs due to thrombosis. Patients with platelet hyperreactivity have increased risk of thromboembolic events, including graft occlusion, myocardial infarction and stroke. Therefore intensifying the antiplatelet therapy in these patients, must be anticipated to have beneficial effects. Hypercoagulable patients are identified with thrombelastography(TEG) as having a Maximal Amplitude(MA)>69, thereafter randomized to either clopidogrel(3months) and aspirin or aspirin alone. At 3 months postoperative after surgery the coronary graft patency is assessed with Multislice CT scan. Pre- and postoperatively, and then again at 3month followup, TEG and multiplate aggregometry are performed to assess platelet reactivity and resistance to aspirin and clopidogrel.

Official Title
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ThrombElastoGraphic Haemostatic Status and Antiplatelet Therapy After Coronary Artery Bypass Graft Surgery(TEG-CABG Trial):Does Intensified Postoperative Antiplatelet Therapy in Preoperatively Identified Hypercoagulable Patients Improve Outcome After CABG Surgery

Conditions
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Graft Patency, Coronary Artery Bypass Grafting Surgery, Hypercoagulability, Thrombosis

Intervention / Treatment
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* Drug: Clopidogrel+acetylsalicylic acid
* Drug: acetylsalicylic acid


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective/subacute multivessel CABG Isolated CABG procedure, no concomitant surgery age > 18 years Able to give informed consent Exclusion Criteria: Myocardial infarction <48h of surgery Prior CABG surgery within 1 month Cardiac Shock within 48h of surgery Atrial fibrillation Anticoagulation therapy with VKA ICH/TCI within 30 days Prior peptic ulcer· Platelet count < 150 E9 Ongoing bleeding Known platelet disease Allergic to aspirin or clopidogrel Liver disease with elevated ALAT/ASAT> 1,5x normal Creatinine> 0,120mmol/l Contrast allergy Alcohol or narcotics abuse Pregnancy Not able to give informed consent Geographically not available for follow up

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 |
| --- | --- |
| Experimental: Clopidogrel+Aspirin, hypercoagulabel<br> | Drug: Clopidogrel+acetylsalicylic acid<br>* loading dose clopidogrel 300mg on second postoperative day. Thereafter 75mg clopidogrel daily for 3 months Aspirin 75mg daily, started within 24 hours after surgery<br>* Other names: Plavix;|
| Active Comparator: Aspirin,hypercoagulabel control<br> | Drug: acetylsalicylic acid<br>* aspirin 75 mg daily, started 6-24 hours after surgery<br>* Other names: Magnyl;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Graft patency at 3 months | Graft patency of Saphenous vein grafts will be significantly higher in TEG-Hypercoagulable patients on clopidogrel+aspirin vs. aspirin alone. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of other thromboembolic events( e.g. myocardial infarction,stroke, pulmonary embolus etc.)and cardiovascular death | In the TEG-Hypercoagulable intervention group (clopidogrel+aspirin) we expect significantly lower rates, of other thromboembolic events (e.g. myocardial infarction,stroke, pulmonary embolism etc) and cardiovascular death, compared to TEG-Hypercoagulable patients on aspirin monotherapy. | 3 months | 
| Assessing coagulation profile pre- and postoperatively, including aspirin and clopidogrel resistance |  | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Aspirin, Saphenous vein, Antiplatelet therapy, Hypercoagulable, Clopidogrel resistance, Aspirin resistance, Clopidogrel, Saphenous vein graft disease, TEG, Thrombelastography, Multiplate aggregometry, Multislice CT, Coronary artery bypass graft surgery, coagulation status, graft patency, CABG