Existe-t-il une « résistance » biologique au traitement antiplaquettaire associant aspirine et clopidogrel chez les patients ayant présenté une occlusion de stent ?

Abstract

Interindividual variability of biological response to antiplatelet agents is an opened question, which constitute the purpose of recent publications. Indeed, a wide interindividual variability in the laboratory response to antiplatelet agents such as aspirin and/or clopidogrel has been shown. However, only few clinical data are available to demonstrate the relationship between a poor laboratory response to antiplatelet treatment and the occurrence of stent thrombosis. The aim of this study is to compare photometric platelet aggregation profiles of two groups of patients who had undergone percutaneous coronary intervention with stent implantation (one group with at least one subacute thrombotic event following stent implantation and one historical control group free of thrombotic events) to determine whether there is a parameter which could be useful in identifying patients with a risk of having a thrombotic event related to poor response to antiplatelet treatment. We found some differences between the two groups regarding the maximal light transmission after stimulation with arachidonic acid (1,39 mM) or collagen at low concentration (Horm, 2 microg/mL) but not after stimulation with ADP irrespective of the concentration studied (10, 5 and 2,5 microM). However, platelet inhibition response to ADP could be assessed with another parameter, the disaggregation percentage, which was significantly lower in patients with than without thrombosis, and may be used as marker to distinguish patients with a higher risk of thrombosis.