简介：BackgroundTheremaybedysregulationofcirculatingmicroRNAsinacutemyocardialinfarction(AMI),whichisanaging-relatedprocess.However,thedifferencebetweenyoungandelderlypeopleinexpressionlevelofcirculatingmiR-21inAMIpatientshasnotbeeninvestigated.MethodsThestudyincluded72consecutivepatientswithAMI.ThegroupIconsistedof43patientsagedequaltoorabove65yearsandthegroupIIconsistedof29patientsagedequaltoorbelow45years.Real-timeRT-PCRwasappliedtodetectserummiR-21expressionlevelsatthetimeofmechanicalreperfusionand12h,D1,D3andD7afterPCI,respectively.ResultsTheexpressionlevelofmiR-21inAMIpatientsincreasedmarkedly12hafterPCIandreachedthepeakatD1afterPCIinbothgroups.TherewasnodifferenceofmiR-21expressionbetweenGroupⅠandⅡatthetimeofmechanicalreperfusion(5.12±0.73vs.4.98±0.87)andD7afterPCI(1.28±0.75vs.1.94±0.89),However,groupⅠpatientsexhibitedhighermiR-21expressionlevelthangroupⅡat12h(7.96±0.78vs.4.23±0.77,P<0.05),D1(9.32±0.89vs.6.12±0.92,P<0.05)andD3(4.78±0.91vs.2.97±0.77,P<0.05)afterPCI,respectively.ConclusionOurdatarevealanincreaseofmiR-21inpatientswithAMImaybeamechanismofmyocardialischemiareperfusioninjury.TheexpressionofmiR-21wasrelatedtothedevelopmentandprogressionofAMI,andthereisanage-relatedchangeintheexpressionofmiR-21inacutemyocardialinfarctionpatients.