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Platelet Reactivity in Stent Thrombosis Patients (MAPCAT)

This study has been completed.
University of Cologne
Information provided by (Responsible Party):
J.M. ten Berg, St. Antonius Hospital Identifier:
First received: November 12, 2009
Last updated: August 22, 2011
Last verified: August 2011
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.

Condition Intervention Phase
Coronary Artery Stent Thrombosis
Drug: Clopidogrel
Phase 4

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: 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).

Resource links provided by NLM:

Further study details as provided by St. Antonius Hospital:

Primary Outcome Measures:
  • 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 ]

Secondary Outcome Measures:
  • 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. ]
  • 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 ]

Enrollment: 187
Study Start Date: April 2009
Study Completion Date: December 2009
Primary Completion Date: December 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: stent thrombosis patients
Patients with a history of a stent thrombosis
Drug: Clopidogrel
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 Name: Plavix
Active Comparator: Patients without a history of a stent thrombosis
Patients without a history of stent thrombosis
Drug: Clopidogrel
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 Name: Plavix

Detailed Description:


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.


Ages Eligible for Study:   18 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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
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Please refer to this study by its identifier: NCT01012544

St Antonius Hospital
Nieuwegein, Utrecht, Netherlands, 3435CM
Sponsors and Collaborators
St. Antonius Hospital
University of Cologne
Principal Investigator: J.M. ten Berg, MD, PhD St Antonius center for platelet function research
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: J.M. ten Berg, Cardiologist, MD, PhD, FESC, FACC, St. Antonius Hospital Identifier: NCT01012544     History of Changes
Other Study ID Numbers: MAPCAT01
Study First Received: November 12, 2009
Last Updated: August 22, 2011

Keywords provided by St. Antonius Hospital:
platelet function tests
platelet reactivity

Additional relevant MeSH terms:
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Platelet Aggregation Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Fibrinolytic Agents
Fibrin Modulating Agents
Cytochrome P-450 CYP2C19 Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Enzyme Inhibitors processed this record on April 26, 2017