ObjectivesToinvestigatethechangeandclinicalsignificanceofclopidogrelonplateletmembraneCD40Lincoronaryarterydiseasepatientsbeforeandafterpercutaneouscoronaryintervention(PCI).Methods30caseswhowerediagnosiscoronaryarterydiseases(CAD)bycoronaryangiography,meanage56±9yearsold.Allthepatientswhohadnoantiplateletaggregationcontraindication,weretreatedwithstandardantianginapectorisdrugs.BeforePCI,allthepatientstookclopidogrel75mgperday.ActivatedplateletmembraneCD40LexpressratewasmeasuredbyflowcytometrybeforeandafterPCI6hours.ResultsActivatedplateletmembraneCD40Lexpressratewere3.73±2.15and2.46±0.90,respectivelyin30patientsbeforeandafterPCI6hours.ActivatedplateletmembraneCD40LexpressratewassignificantlydecreaseafterPCI6hoursthanthatbeforePCI(P<0.01).ConclusionsClopidogrelhassignificanceeffectonplateletmembraneCD40LincoronaryarterydiseasepatientsundergoingPCI.Clopidogrelcansuppressionplateletactivationandpreventthromboembolismeventoccurrence.