简介：BackgroundCreatinekinase-MB(CK-MB)elevationafterpercutaneouscoronaryintervention(PCI)hasbeenassociatedwithincreasedriskformortality.Althoughmoststudieshavedefinedperiproceduralmyocardialinfarction(pMI)asanelevationinCK-MB>3×upperlimitofnormal(ULN),useofdifferentCK-MBassaysandvariationinsite-specificdefinitionsoftheULNmaylimitthevalueofsuchrelativethresholds.MethodsandResultsWeuseddatafromthemulticenterEvaluationofDrug-ElutingStentsandIschemicEvents(EVENT)registrytoexaminetheimpactofvariationsinsite-specificthresholdsforCK-MBelevationontheincidenceofpMIaswellastherelationshipbetweenabsolutepeaklevelsofCK-MBafterPCIand1-yearmortality.Thestudycohortconsistedof6347patientswhounderwentnonemergentPCIandhadnormalCK-MBatbaseline.Acrossthe59studycenters,theULNforCK-MBrangedfrom2.6to10.4ng/mL(median,5.0ng/mL),andtherewasaninverserelationshipbetweenthesite-specificULNandtheincidenceofpMI(definedasCK-MBelevation>3×ULN).AlthoughanypostprocedureelevationofCK-MBwasassociatedwithanadverseprognosis,incategoricalanalyses,onlyCK-MB≥50ng/mLwasindependentlyassociatedwithincreased1-yearmortality(hazardratio,4.71;95%confidenceinterval,2.42to9.13;P<0.001).SplineanalysisusingpeakCK-MBasacontinuousvariablesuggestedagraded,nonlinearrelationshipwith1-yearmortality,withaninflectionpointat≈30ng/mL.ConclusionsAmongunselectedpatientsundergoingPCI,thereisagradedrelationshipbetweenCK-MBelevationafterPCIand1-yearmortalitythatisparticularlystrongforlargeCK-MBelevations(>30to50ng/mL).FuturestudiesthatincludepMIasaclinicalendpointshouldconsiderusingacorelaboratorytoassessCK-MB(toensureconsistency)andraisingthethresholdfordefiningpMIabovecurrentlevels(toenhanceclinicalrelevance).