Efficacy of Adjusted Clopidogrel Dose in Patients With Insufficient Platelet Inhibition

June 29, 2006 updated by: University Heart Center Freiburg - Bad Krozingen

Efficacy of Adjusted Clopidogrel Dose in Patients With Insufficient Platelet Inhibition After Elective Coronary Stenting

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment

120

Phase

  • Not Applicable

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

  • Germany
      • Bad Krozingen, Germany, 79189
        • Heart Center Bad Krozingen,

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

Description

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

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: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Antiplatelet effect after fourteen and twenty-eight days determined by optical aggregometry after stimulation with ADP

Secondary Outcome Measures

Outcome Measure
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

Collaborators and Investigators

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

Sponsor

University Heart Center Freiburg - Bad Krozingen

Investigators

  • Study Director: Franz-Josef Neumann, MD, Heart Center Bad Krozingen, Germany

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

December 1, 2005

Study Completion

June 1, 2006

Study Registration Dates

First Submitted

March 14, 2006

First Submitted That Met QC Criteria

March 14, 2006

First Posted (Estimate)

March 15, 2006

Study Record Updates

Last Update Posted (Estimate)

July 4, 2006

Last Update Submitted That Met QC Criteria

June 29, 2006

Last Verified

February 1, 2006

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HZ-BK-2005-2

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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