Genetic testing and antiplatelet treatment: Still way to go?

Despite medical and technical advancements stent thrombosis continued to poses a significant risk in patients after drug eluting stent (DES) implantation and clopidogrel resistance has been recognized as an important determinant of this risk. Novel antiplatelets such as prasugrel and ticagrelor can be used in cases of clopidogrel resistance however bleeding complications remain the Achilles' heel of antiplatelet therapy. Several genetic polymorphisms affect the clopidogrel absorption and bio-activation in the active form of the drug. CYP2C19 is responsible for most of the clopidogrel bio-transformation and loss of function as well as, gain of function polymorphisms of this enzyme has been recognized. Early studies have linked CYP2C19 genetic polymorphisms with clinical events, although, these findings were not confirmed by later studies. However, when the estimated thrombotic risk is high a combination of genetic information and functional platelet tests should be essential for clinicians to access clopidogrel effectiveness and to recommend alternative antiplatelet management.