The Protective Effect Of Edaravone Against Myocardial Ischemia-reperfusion Injury In Patients Undergoing Cardiac Valve Replacement Surgery With Cardiopulmonary Bypss(CPB)

Objective:To evaluate the protective effect of edaravone againstmyocardial ischemia-reperfusion injury in patients undergoing cardiac valvereplacement surgery with cardiopulmonary bypss（CPB）.Methods:Thirty patients undergoing cardiac valve replacement surgery w-ith CPB were randomly divided into two groups,test group （n=15）and controlgroup （n=15）.There is no remarkable difference between the two groups inage,body weight,sex ratio,heart function,LVEF.The patients in test group received respectively0.5mg edaravone injectionperkilogram body weigt in the cold blood cardioplegic solution of cardiopulm-onary bypass unit at5min after anesthesia induction before operation;Whilethose in control group received the sallle volume of0.9％normal saline.Themethods of CPB and infusion in the two groups were the same.Blood samples were taken from the radial artery blood at the followingtime points:（1）after anesthesia induction before operation（T1）;（2）instantlyafterCPB （T2）;（3）8hours after CPB（T3）;（4）24hours after CPB（T4）;ThenThecontent of LDH,CK-MB,cTnI,SOD,MDA in plasma of all blood samples wastest,and collected1.0mmXl.0mmXl.0mm myocardial samples of right atrialappendage in patients with ischemic central area （control group withcorresponding parts of the heart）15min after opening aorta in CPB and sendedthem to the electron microscope room of neurology in our hospital to observethe mitochondria ultrastructure by transmission electron microscope.In themean time,we observed and recorded some indexes of the two groups:the CPBtime,aorta-occlusion time,supplementary circulation time,the incidence ofspontaneous recovery of heart,the incidence of postoperative arrhythmias andthe mean dose of dopamine in24hours after operation. Results:1There is no striking difference between the two groups in thecardiopulmonary bypass time，the aorta-occlusion time and the supplementarycirculaton time（P>0.05）．2The incidence of spontaneous recovery of heart in test group afteraorta-unclamping was73.33%,whereas the same index in control group was26.67％.The incidence of spontaneous recovery of heart in test group afteraorta-unclamping was higer than that of control group,The difference betweenthe two groups was significant（P<0.05）．3The incidence of postoperative arrhythmias in24hours after operation intest group Was20.00%,while that control group was66.67%.The incidence ofarrhythmia in24hours after operation in test group was lower than that of co-ntrol group,The difference between the two groups was significant （P<0.05）．4The average dose of dopamine in24hours after operation in test groupwas4.06±1.08ug.kg^-1min^-1and that in control group was5.93±1.49ug.kg^-1min^-1;the average dose of adrenaline in24hours after operation in testgroup was lower than that of control group,The difference between the twogroups was significant（P<0.05）.5The within group comparisons:The content of LDH,CK-MB,cTnI in testgroup respectively in T2,T3,T4were increased in T1,The difference was verysignificant （P<0.01）,The control group was the same.The comparison between groups:Between the two groups The content ofLDH,CK-MB,cTnI were no difference in T1（P>0.05）,But the content ofLDH,CK,CK-MB in test group respectively in T2,T3,T4were lower than thecontrol group,the difference was very significant （P<0.01）.6The within group comparisons:The content of SOD in test grouprespectively in T2,T3,T4were decreased in T1,The difference was significantor very significant （P<0.05or0.01）,The control group was the same, meanwhilethe content of MDA in test group respectively in T2,T3,T4were increased inT1,very significant difference （P<0.01）,The control group was also the same.The comparison between groups:Between the two groups the content ofMDA,SOD were no difference in T1（P>0.05）, But the content of SOD in test group respectively in T2,T3,T4were higer than the control group,thedifference was significant （P<0.05）.and the content of MDA in test grouprespectively in T2,T3,T4were lower than the control group,the difference wasvery significant （P<0.01）.7Myocardial ultrastructure:The test group myocardial fibers arrangedregularly with continuous,Z line is clear,the mitochondrial structure iscomplete,clear,ridge arranged more orderly,ridge gap is obvious,however thecontrol group myocardial fibers arranged obvious disorder,fracture,part or allof the muscle fiber dissolution,Z line blurred,mitochondrial swelling,andvacuolar degeneration,so the degree of myocardial cell injury was moresignificantly compared with test group.Conclusions:Earavone can decrease significantly the plasma levels ofLDH,CK-MB,cTnI and MDA,increase the activity of SOD,and can signify-cantly reduce injury in myocardial tissue and myocardial cells,reducingmyocardial inchemia-reperfusion injury.It has good effects on myocardialprotection in CPB in patients undergoing cardiac valve replacement.