Platelet Inhibition in the Acute Phase of STEMI

September 6, 2013 updated by: University of Aarhus

Platelet Inhibition in the Acute Phase of ST-segment Elevation Myocardial Infarction

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.

Study Overview

Status

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

46

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Denmark
    • Central Denmark Region
      • Aarhus N, Central Denmark Region, Denmark, 8200
        • Aarhus University Hospital, Skejby

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Residents of the Central Denmark Region.

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Only
  • Time Perspectives: Prospective

Cohorts and Interventions

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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months
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.
Approximately 2-3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Aarhus

Collaborators

AP Moeller Foundation

Investigators

  • Principal Investigator: Steen D Kristensen, MD, DMSc, Aarhus University Hospital Skejby

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2009

Primary Completion (Actual)

July 1, 2010

Study Completion (Actual)

August 1, 2010

Study Registration Dates

First Submitted

March 26, 2010

First Submitted That Met QC Criteria

June 15, 2010

First Posted (Estimate)

June 16, 2010

Study Record Updates

Last Update Posted (Estimate)

September 9, 2013

Last Update Submitted That Met QC Criteria

September 6, 2013

Last Verified

September 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 23374

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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