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Efficacy of Adjusted Clopidogrel Dose in Patients With Insufficient Platelet Inhibition

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00302913
First Posted: March 15, 2006
Last Update Posted: July 4, 2006
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.
Information provided by:
Heart Center Bad Krozingen
  Purpose
This study is a prospective, single-center evaluation of the efficacy of clopidogrel dose adjustment in patients with insufficient platelet inhibition after elective coronary stent implantation.

Condition Intervention
Coronary Artery Disease Drug Resistance Drug: Adjustment of clopidogrel dose

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Efficacy of Adjusted Clopidogrel Dose in Patients With Insufficient Platelet Inhibition After Elective Coronary Stenting

Resource links provided by NLM:


Further study details as provided by Heart Center Bad Krozingen:

Primary Outcome Measures:
  • Antiplatelet effect after fourteen and twenty-eight days determined by optical aggregometry after stimulation with ADP

Secondary Outcome Measures:
  • Antiplatelet effect after fourteen and twenty-eight days determined by flow cytometric evaluation of surface protein expression after stimulation with ADP
  • Major cardiac events within thirty days (death, myocardial infarction, target vessel reintervention)
  • Bleeding and vascular access site complications within thirty days
  • Drug-drug interaction of clopidogrel with concomitant treatment

Estimated Enrollment: 120
Study Start Date: December 2005
Estimated Study Completion Date: June 2006
Detailed Description:

Background: The EXCELSIOR trial demonstrated a 7-fold increased risk for death, myocardial infarction and target vessel reintervention within 30 days in patients with platelet inhibition below median of study cohort after a bolus dose of 600 mg of clopidogrel. The median of platelet inhibition in this cohort was 14 % optical aggregation after stimulation with 5 µM ADP.

Aim: To evaluate the efficacy of clopidogrel dose adjustment in patients with insufficient platelet inhibition after elective coronary stent implantation

Methods: This prospective, single-center study will evaluate antiplatelet effects in 120 patients receiving a bolus dose of 600 mg of clopidogrel before undergoing elective coronary stent implantation. Platelet inhibition will be evaluated 24 hours, 14 and 28 days after coronary intervention using optical aggregometry (5 µM ADP) and determination of surface protein expression by flow cytometry (P-Selectin, gp55, activated GP IIb/IIIa). If 24 hours after coronary stent implantation optical aggregation is >14 %, patients will receive an additional bolus dose of 300 mg of clopidogrel, followed by a daily dose of 150 mg for at least 28 days. If optical aggregation at this point of time is ≤14 % patients will receive a daily dose of 75 mg of clopidogrel. No further dose adjustments during follow up will be performed.

Hypothesis: Adjustment of clopidogrel dose in patients with insufficient platelet inhibition determined by optical aggregometry will provide a comparable antiplatelet effect as in patients with sufficient platelet inhibition after coronary stent implantation.

  Eligibility

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Patients undergoing elective coronary stenting
  • Pretreatment with a bolus dose of 600mg of clopidogrel at least 2 hours prior to coronary stent implantation
  • Pretreatment with aspirin ≥ 100 mg per day for at least 7 days
  • Age > 18 years
  • Written consent

Exclusion Criteria:

  • Troponin T on admission > 0.03 ng/mL
  • Myocardial infarction or fibrinolytic therapy within the previous 14 days
  • Cardiogenic shock
  • Contraindication for aspirin or clopidogrel
  • Oral anticoagulation
  • Pretreatment with heparin or a thienopyridine within the previous 14 days
  • Use of a GP IIb/IIIa-receptor antagonist during PCI
  • Platelet count < 100.000/µl
  • Severe disorders of the coagulation system
  • Severe impairment of liver or kidney function
  • Cancer
  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): NCT00302913


Locations
Germany
Heart Center Bad Krozingen,
Bad Krozingen, Germany, 79189
Sponsors and Collaborators
Heart Center Bad Krozingen
Investigators
Study Director: Franz-Josef Neumann, MD Heart Center Bad Krozingen, Germany
  More Information

ClinicalTrials.gov Identifier: NCT00302913     History of Changes
Other Study ID Numbers: HZ-BK-2005-2
First Submitted: March 14, 2006
First Posted: March 15, 2006
Last Update Posted: July 4, 2006
Last Verified: February 2006

Keywords provided by Heart Center Bad Krozingen:
Clopidogrel
Coronary Artery Disease
Dose-Response Relationship, Drug
Drug Resistance
PCI

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arteriosclerosis
Arterial Occlusive Diseases
Vascular Diseases
Clopidogrel
Ticlopidine
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