Platelet Reactivity in Stent Thrombosis Patients (MAPCAT)

August 22, 2011 updated by: J.M. ten Berg, St. Antonius Hospital

The MAgnitude of Platelet Inhibition and the Pharmacokinetics of a 600 mg Loading Dose of Clopidogrel, in Different Patient CATegories (Stable Angina Versus Acute-coronary Syndromes Versus ST-elevated Myocardial Infarction).

Recent studies have demonstrated a marked interindividual variability of clopidogrel's capacity to inhibit platelet aggregation with a substantial proportion (11-34%) of the patients considered non-responders to clopidogrel treatment. Variable intestinal absorption is suggested to contribute to the inconsistencies in response to clopidogrel. However, little is known about intestinal absorption in subjects who had suffered from a stent thrombosis. The MAPCAT-study has been designed to investigate whether plasma pharmacokinetics (represented by Cmax, Tmax and the AUC) after a 600 mg loading dose are significantly different between subjects who have suffered a stent thrombosis and subjects who have not suffered a stent thrombosis.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

Objectives:

The first objective of the MAPCAT-study is to investigate whether plasma pharmacokinetics (Cmax, Tmax and AUC) of an additional 600 mg loading dose are impaired in patients with a history of stent thrombosis.

The second objective of the MAPCAT study is to investigate whether genetic polymorphisms in receptors, enzymes and ligands involved in the process of thrombosis and haemostasis as well in the conversion-process of clopidogrel into its metabolites do have influence on both the absolute magnitude of platelet inhibition and Cmax, Tmax and AUC.

Study Type

Interventional

Enrollment (Actual)

187

Phase

  • Phase 4

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

    • Utrecht
      • Nieuwegein, Utrecht, Netherlands, 3435CM
        • St Antonius Hospital

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 to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with a history of a stent thrombosis in the period 2004-2008.

Exclusion Criteria:

  • Persistent acute ST-segment elevation
  • Successful revascularization during the qualifying hospitalization, prior to study entry
  • Acute pulmonary edema, hypotension, or evidence of cardiogenic shock
  • Clinically significant liver disease
  • End stage kidney disease requiring dialysis
  • Use at study entry of drugs that are strong inhibitors of cytochrome P450 3A4 and CYP3A5 (i.e. clarithromycin, erythromycin, itraconazole, ketoconazole)
  • Contraindications to antithrombotic/antiplatelet therapy
  • Failed coronary intervention in the previous 2 weeks
  • Malignancies
  • Increased risk of bleeding (previous stroke in the past months, active bleeding or bleeding diathesis, recent trauma or major surgery in the last month, suspected aortic dissection, oral anticoagulation therapy with coumarin derivate within 7 days, recent use of GPIIb/IIIa inhibitors within 14 days, severe uncontrolled hypertension >180 mmHg unresponsive to therapy)
  • Relevant hematologic deviations (haemoglobin <100g/L (6,2 mmol/L) or hematocrit <34%, platelet count <100 x 109 /L or platelet count > 600 x 109/L)
  • Known allergy to clopidogrel
  • Pregnancy (present or suspected)
  • uncontrolled hypertension at time of randomization

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

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: stent thrombosis patients
Patients with a history of a stent thrombosis
both arms of the study (patients with a history of stent thrombosis as well as patients who did not suffer from a stent thrombosis) will be given a 600 mg loading dose of clopidogrel
Other Names:
  • Plavix
Active Comparator: Patients without a history of a stent thrombosis
Patients without a history of stent thrombosis
both arms of the study (patients with a history of stent thrombosis as well as patients who did not suffer from a stent thrombosis) will be given a 600 mg loading dose of clopidogrel
Other Names:
  • Plavix

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Plasma concentrations of unchanged clopidogrel, its active thiol metabolite and its inactive carboxyl metabolite between the different patient groups after the administration of a 600 mg loading dose of clopidogrel.
Time Frame: 6 hours after the administration of a 600mg loading dose of clopidogrel
6 hours after the administration of a 600mg loading dose of clopidogrel

Secondary Outcome Measures

Outcome Measure
Time Frame
The magnitude of platelet reactivity as measured with several commercial available platelet function tests before and 6 hours after the ingestion of the loading dose.
Time Frame: platelet reactivity measured at baseline and 6 hours after a 600 mg clopidogrel loading dose.
platelet reactivity measured at baseline and 6 hours after a 600 mg clopidogrel loading dose.
Exploratory Endpoint: prevalence of various genetic polymorphisms that might influence the pharmacokinetics of clopidogrel
Time Frame: blood obtained for genetic sampeling at timepoint of first study blood collection
blood obtained for genetic sampeling at timepoint of first study blood collection

Collaborators and Investigators

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

Collaborators

Investigators

  • Principal Investigator: J.M. ten Berg, MD, PhD, St Antonius center for platelet function research

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

April 1, 2009

Primary Completion (Actual)

December 1, 2009

Study Completion (Actual)

December 1, 2009

Study Registration Dates

First Submitted

November 12, 2009

First Submitted That Met QC Criteria

November 12, 2009

First Posted (Estimate)

November 13, 2009

Study Record Updates

Last Update Posted (Estimate)

August 23, 2011

Last Update Submitted That Met QC Criteria

August 22, 2011

Last Verified

August 1, 2011

More Information

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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