Effect of Abrupt Plavix® Discontinuation on Platelet Function

Université de Montréal

Status

Completed

Conditions

Coronary Artery Disease

Treatments

Other: Platelet function testing

Study type

Observational

Funder types

Other

Identifiers

NCT00670943

C.E. 2007-05-41

Details and patient eligibility

About

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.

Enrollment

52 estimated patients

Sex

All

Ages

18 to 90 years old

Volunteers

No Healthy Volunteers

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