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Platelet Inhibition in the Acute Phase of STEMI

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT01144819
Recruitment Status : Completed
First Posted : June 16, 2010
Last Update Posted : September 9, 2013
Sponsor:
Collaborator:
Information provided by (Responsible Party):

Study Description
Brief Summary:

Background:

Dual antithrombotic treatment with aspirin and clopidogrel is recommended in patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The European Society of Cardiology (ESC) Guidelines recommend a bolus dose of aspirin of 250-500 mg and a 600 mg bolus dose of clopidogrel as soon as STEMI is suspected. Studies have shown that more newly produced platelets are present in the acute phase of STEMI, and it is likely that these immature platelets are haemostatically more active and might be of importance in thrombus formation.

The enhanced platelet reactivity may reduce the effect of aspirin and clopidogrel in the acute phase of STEMI compared to measurements made in the same patients 3 months after primary PCI.

Aim:

This study aims to compare platelet response to aspirin and clopidogrel in the acute phase of STEMI with the platelet response in the same patients 3 months after STEMI .

Design:

This study is an observational follow-up study.

Materials and methods:

46 patients with STEMI referred to primary PCI at Aarhus University Hospital, Skejby will be included in the study. A total of 3 blood samples are obtained in the acute phase of STEMI: Prior to primary PCI (Blood sample 1), at 4 hours (Blood sample 2) and at 12 hours (Blood sample 3) after administration of loading dose aspirin and clopidogrel. When patients are in a stable phase 3 month later, a final blood sample is taken (Blood sample 4). The blood is analyzed 30 minutes after withdrawal of blood by the platelet aggregation test Multiplate® aggregometry (agonists: Collagen, arachidonic acid and adenosinediphosphate) and VerifyNow® arachidonic acid and P2Y12 aggregometry. Platelet count, volume and the immature platelet fraction (IPF) will be measured using Sysmex® flowcytometry.


Condition or disease
Acute Myocardial Infarction Antiplatelet Therapy ST-segment Elevation Myocardial Infarction (STEMI)

Study Design

Study Type : Observational
Actual Enrollment : 46 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Platelet Inhibition in the Acute Phase of ST-segment Elevation Myocardial Infarction
Study Start Date : October 2009
Primary Completion Date : July 2010
Study Completion Date : August 2010

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Attack
U.S. FDA Resources

Groups and Cohorts

Group/Cohort
STEMI
Patients with STEMI according to ESC STEMI guidelines: Age above 18 years and able to give written, informed consent to participation in the project.


Outcome Measures

Primary Outcome Measures :
  1. Difference between aggregation induced by agonist collagen (1 μg/ml) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  2. Difference between aggregation induced by agonist collagen (1 μg/ml) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  3. Difference between aggregation induced by agonist collagen (1 μg/ml) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  4. Difference between aggregation induced by agonist arachidonic acid (1,0 mM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  5. Difference between aggregation induced by agonist arachidonic acid (1,0 mM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  6. Difference between aggregation induced by agonist arachidonic acid (1,0 mM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  7. Difference between aggregation induced by agonist adenosine diphosphate (6,4 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  8. Difference between aggregation induced by agonist adenosine diphosphate (6,4 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  9. Difference between aggregation induced by agonist adenosine diphosphate (6,4 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  10. Difference between aggregation induced by agonist adenosine diphosphate (20 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  11. Difference between aggregation induced by agonist adenosine diphosphate (20 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  12. Difference between aggregation induced by agonist adenosine diphosphate (20 µM) measured by Multiplate® Aggregometry (Unit=AUC). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  13. Difference between aggregation measured by VerifyNow® Aggregometry using the ASPI-kit (Unit = ARU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  14. Difference between aggregation measured by VerifyNow® Aggregometry using the ASPI-kit (Unit = ARU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  15. Difference between aggregation measured by VerifyNow® Aggregometry using the ASPI-kit (Unit = ARU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  16. Difference between aggregation measured by VerifyNow® Aggregometry using the P2Y12-kit (Unit = PRU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after primary PCI.


  17. Difference between aggregation measured by VerifyNow® Aggregometry using the P2Y12-kit (Unit = PRU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  18. Difference between aggregation measured by VerifyNow® Aggregometry using the P2Y12-kit (Unit = PRU). [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between aggregation measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.



Secondary Outcome Measures :
  1. Difference in immature platelet fraction measured by Sysmex® flowcytometry. [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after administration of LD aspirin and clopidogrel.


  2. Difference in serum P-selectin [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after administration of LD aspirin and clopidogrel.


  3. Difference in serum trombopoietin [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after administration of LD aspirin and clopidogrel.


  4. Difference in serum thromboxane B2 [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 1: Obtained immediately before primary PCI in the catherization laboratory. The blood sample is obtained from the femoral artery catheter.

    Blood sample 4: 2-3 months after administration of LD aspirin and clopidogrel.


  5. Difference in immature platelet fraction measured by Sysmex® flowcytometry. [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 2: 4 hours after administration of loading dose (LD) aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.


  6. Difference in immature platelet fraction measured by Sysmex® flowcytometry. [ Time Frame: Approximately 2-3 months ]

    Outcome is the difference between measurements. In this case between:

    Blood sample 3: 12 hours after administration of LD aspirin and clopidogrel.

    Blood sample 4: 2-3 months after primary PCI.



Biospecimen Retention:   Samples With DNA

Blood sample 1:

  • Whole blood (Platelet aggregation tests and flowcytometry)
  • Serum
  • S-Thromboxane B2
  • S-Trombopoeitin
  • S-P-selectin
  • Plasma
  • DNA
  • RNA

Blood sample 2:

  • Whole blood
  • Plasma

Blood sample 3:

  • Whole blood
  • Plasma

Blood sample 4:

  • Whole blood (Platelet aggregation tests and flowcytometry)
  • Serum
  • S-Thromboxane B2
  • S-Trombopoeitin
  • S-P-selectin
  • Plasma
  • DNA
  • RNA

Eligibility Criteria

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Residents of the Central Denmark Region.
Criteria

Inclusion Criteria:

  • Above 18 years of age
  • Patients with ST-segment elevation myocardial infarction (STEMI) referred to primary PCI at University Hospital of Aarhus, Skejby.

Exclusion Criteria:

  • Treatment with NSAID, ticlopidine and dipyramidole.
  • Treatment with anticoagulants (Vitamin K antagonists)
  • Patients diagnosed with platelet disease or haemophilia.
  • Patients unable to give written, informed consent to participation in this project.
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01144819


Locations
Denmark
Aarhus University Hospital, Skejby
Aarhus N, Central Denmark Region, Denmark, 8200
Sponsors and Collaborators
University of Aarhus
AP Moeller Foundation
Investigators
Principal Investigator: Steen D Kristensen, MD, DMSc Aarhus University Hospital Skejby
More Information

Publications:
Responsible Party: University of Aarhus
ClinicalTrials.gov Identifier: NCT01144819     History of Changes
Other Study ID Numbers: 23374
First Posted: June 16, 2010    Key Record Dates
Last Update Posted: September 9, 2013
Last Verified: September 2013

Keywords provided by University of Aarhus:
STEMI
Acute myocardial infarction
Antiplatelet therapy
aspirin
clopidogrel
VerifyNow aggregometry
Multiplate aggregometry

Additional relevant MeSH terms:
Infarction
Myocardial Infarction
ST Elevation Myocardial Infarction
Ischemia
Pathologic Processes
Necrosis
Myocardial Ischemia
Heart Diseases
Cardiovascular Diseases
Vascular Diseases