Thromboelastography As An Assessment Tool for Possible Clopidogrel and Aspirin Resistance (TEG)

Thromboelastography As An Assessment Tool for Possible Clopidogrel and Aspirin Resistance in The Patients Treated With Primary PCI for STEMI

TEG is an established technique to assess the quality of clot formation' used mainly in surgery and obstetrics to determine possible bleeding diathesis. Recently it became to be used in cardiology, where it can be a valuable tool to assess a response to antiplatelet therapy and its association with the outcome. However, there is a few data about use of TEG in STEMI patients undergoing PCI. Our study is designed to assess by TEG the platelet's response to clopidogrel treatment during acute STEMI in patients undergoing primary PCI and the correlation of this response with the long term outcome, and ability to dose adjustment according to a specific measurement by TEG in order to prevent future MACE.

TEG system may provide the capabilities needed to deliver personalized therapy, first, because it can identify patients at risk of ischemic event based on hemostatic influences, particularly platelet aggregation and platelet reactivity. Secondly, because treating those patients who exhibit high platelet reactivity -- an indication that they are not reaching a therapeutic level -- with appropriate drugs and doses is expected to improve outcomes. In this study that would be increased clopidogrel maintenance dosing (150 mg) or aspirin maintenance dosing to 200mg in an attempt to lower platelet reactivity below the 50th%ile, which we expect to also reduce their ischemic risk during the follow up period.

Thromboelastography, Aspirin, Clopidogrel, Plavix, Resistance, Platelet, Coronary Stenting, Bare Metal Stent, Dual antiplatelet therapy, Overreactivity, Primary Coronary Intervention

Patients who suffered acute STEMI and were treated by PPCI and by Aspirin 100mg and Plavix 75mg and showed on treatment platelet over-reactivity observed by TEG system on the 5th day after admission to ICCU

Patients who suffered acute STEMI and were treated by PPCI and recieved by Aspirin 100mg and Plavix 75mg and showed platelet inhibition observed by TEG system on the 5th day after admission to ICCU

Non- responders to Aspirin or Plavix shown on TEG analysis will be treated by doubling of Aspirin (200mg) and/or Plavix (150mg) dosage

Responders to standard dual antiplatelet therapy as observed by TEG analysis will continue standard doses of Aspirin and Plavix

To determine usefulness of thromboelastography (TEG) as a valuable tool in assessing platelet response to clopidogrel treatment and post-treatment platelet reactivity during acute ST segment elevation myocardial infarction (STEMI).

To determine the correlation between platelet response to clopidogrel treatment and the outcome of patients who underwent percutaneous coronary intervention (PCI) for STEMI.

Inclusion Criteria: Patients 18 years of age or more Patients admitted with acute STEMI as a first Coronary event Duration of symptoms less than 12 hours PCI elected as a treatment of acute STEMI Informed consent signed Exclusion Criteria: Thrombolytic therapy PCI not performed after diagnostic angiography (conservative treatment, CABG) DES used in PPCI Staged PCI procedures Previous clopidogrel treatment at any time for any reason Previous myocardial infarction Known bleeding diathesis of any kind Significant renal insufficiency (GFR<40 ml/min) LFT disturbances (Transaminase elevation more than x3 ULN) Significant anemia (Hb<10) or a need for blood transfusion Significant Thrombocytopenia (PLT Count < 150000) Known Clopidogrel allergy Known Active peptic disease

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