 The use of thienopyridines in patients undergoing percutaneous coronary intervention PCI has dramatically decreased the rate of early stent thrombosis. Further the CURE trial demonstrated that long-term clopidogrel decreases the rate of major adverse cardiovascular events in acute coronary syndrome patients ACS . However clopidogrel has several limitations including a long delay of action which is a potential limitation in acute settings of coronary artery disease. Another major limitation of the drug is the wide inter individual variability in clopidogrel responsiveness related to various factors. 