Research On High On-treatment Platelet Reactivity And CYP2C19Polymorphisms Up To Six Months After Percutaneous Coronary Interventions

Objective We aimed to investigate the relationship between cytochrome (CYP)2C19*2,*3polymorphisms and high on-treatment platelet reactivity (HPR) in patients treated with percutaneous coronary interventions (PCI) and dual antiplatelet therapy over a6-month period.Methods Totally47patients post-PCI were enrolled in the first affiliated hospital of SooChow university from June2012to September2012. Patients received a300mg loading dose(LD) clopidogrel and aspirin or75mg/d clopidogrel and100mg/d aspirin maintenance dose(MD) before PCI, then continued with clopidogrel and aspirin MD as dual antiplatelet therapy. Max platelet aggregation(MPA) was assessed by light transmittance aggregometry(LTA) following2μmol/L and5μmol/L adenosine diphosphate(ADP) stimili in post-PCI patients after6months. Direct sequence was used to genotype the CYP2C19*2、CYP2C19*3polymorphisms in these patients. HPR was defined as MPA≥46%, whereas those having<46%were nHPR. Basic clinical data, routine examination, PCI details, MPA and CYP2C19polymorphisms were assessed and compared between HPR group and nHPR group. According to CYP2C19polymorphism, we examined MPA and HPR in different phenotype.Results HPR was present in36.2%patients. There were no significant differences between HPR group and nHPR group in basic clinical data, routine examination and PCI characters (P>0.05). Carriers of CYP2C19*1/*1wide-type were21patients(44.7%), carriers of at least one CYP2C19variant allele were18patients(38.3%) and homozygotes of CYP2C19were8patients(17.0%). The phenotype of CYP2C19includes EMs44.7%(n=21), IMs38.3%(n=18) and PMs17.0%(n=8). In HPR group and nHPR group, there were EMs35.3%(n=6)、50.0%(n=15), IMs35.3%(n=6),40.0%(n=12), PMs29.4%(n=5)、10.0% (n=3), respectively. There’s no statistic differences among EMs、IMs、PMs in MPA and HPR distribution.Conclusion1. HPR is common in patients received clopidogrel after PCI.2. MPA measured by LTA can be used to determine the extent of clopidogrel induced plateler inhibition, namely, HPR. We can evaluate clopidogrel response diversity via LTA.3. The carriage prevalence of the CYP2C19loss of function(LOF) variant is relatively high in China.4. It seems no substantial interaction between CYP2C19polymorphism and platelet reactivity on clopidogrel, CYP2C19genotyping in every patients would not be useful in routine PCI practice, require to be validated in further large-scale clinical trials.