Effect of Abrupt Plavix® Discontinuation on Platelet Function

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. Identifier: NCT00670943
Recruitment Status : Completed
First Posted : May 2, 2008
Last Update Posted : March 25, 2009
Hopital du Sacre-Coeur de Montreal
Information provided by:
Université de Montréal

Brief Summary:

The well established importance of regular administration of antiplatelet drugs stands on firm grounds, as large meta-analyses have shown these therapies to significantly reduce the risk of death. Plavix® (clopidogrel) is widely used following coronary angioplasty, to reduce the risk of periprocedural thrombotic complications, for up to one year. As the current recommendations suggest clopidogrel use for no longer than one year, the drug is normally discontinued within that period. In the limited state of knowledge on antiplatelet drug withdrawal, an early sound of alarm has risen from early thromboembolic complications reported after the interruption of antiplatelet treatment used in prevention of ischemic vascular disease. Although little information is available, discontinuation of thienopyridines has been associated with increased thromboembolic complications, mainly acute stent thrombosis. These complications may signal a platelet sensitization effect to aggregating stimuli by antiplatelet drugs taken chronically.

The current study aims to evaluate the impact of clopidogrel discontinuation on platelet function, in order to shed light on underlying mechanisms leading to increased risk of acute thrombo-occlusive events.

Condition or disease Intervention/treatment
Coronary Artery Disease Other: Platelet function testing

Study Type : Observational
Estimated Enrollment : 52 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Effect of Abrupt Plavix® Discontinuation on Platelet Function
Study Start Date : January 2008
Actual Primary Completion Date : March 2009
Actual Study Completion Date : March 2009

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Patients with stable CAD with scheduled discontinuation of clopidogrel
Other: Platelet function testing
Patients with stable CAD not taking clopidogrel
Other: Platelet function testing

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Patients with stable coronary artery disease

Inclusion Criteria:

  • Group 1: Patients suffering from stable CAD scheduled to discontinue clopidogrel therapy at least one month after stent implantation
  • Group 2: Stable clopidogrel-naïve CAD patients
  • Patients willing to participate in the study and to sign the informed consent form

Exclusion Criteria:

  • Acute coronary syndrome or revascularization in the last 3 months prior to enrolment
  • Concurrent ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs, including COX-2 selective anti-inflammatory drugs), ticlopidine, dipyridamole, warfarin or acenocoumarol
  • Major surgical procedure within 1 month before enrolment
  • Platelet count outside the 100 000 to 450 000/μL range
  • Hematocrit < 25% or haemoglobin < 100 g/L
  • Patient undergoing dialysis for chronic renal failure

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 identifier (NCT number): NCT00670943

Canada, Quebec
Hôpital du Sacré-Coeur de Montréal
Montreal, Quebec, Canada, H4J 1C5
Sponsors and Collaborators
Université de Montréal
Hopital du Sacre-Coeur de Montreal
Principal Investigator: Jean G Diodati, MD Hopital du Sacre-Coeur de Montreal

Responsible Party: Jean G. Diodati, Hôpital du Sacré-Coeur de Montréal Identifier: NCT00670943     History of Changes
Other Study ID Numbers: C.E. 2007-05-41
First Posted: May 2, 2008    Key Record Dates
Last Update Posted: March 25, 2009
Last Verified: March 2009

Keywords provided by Université de Montréal:
Clopidogrel discontinuation
Platelet aggregation

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