In the case of antiplatelet pro-drug, clopidogrel, metabolism of the drug is impaired in individuals with loss-of-functions CYP2C19 alleles leading to lower active metabolite exposure [37, 38] and the presence of these alleles in patients with acute coronary syndromes and/or those undergoing percutaneous coronary intervention has been associated with an increase in the rates of cardiovascular events [39, 40]. This evidence concerns the gene CYP2C19 and acute coronary syndrome.