Effect Of Myocardial Protective By Ischemic Preconditioning In Cardiopulmonary Bypass Valve Surgery:a Meta Analysis

Background: Valve heart disease is a common heart disease.Open heart surgery with extracorporeal circulation is still the main prosedure to deal with it.With the improvement of medical level in China,the amount of open heart surgery under extracorporeal circulation is increasing year by year.Studies on how to reduce myocardial injury in open heart valve replacement with extracorporeal circulation are also emerging.In recent years,in clinical studies some scholars have observed that the application of ischemic preconditioning(IPC)technology can effectively reduce the myocardial injury in open heart valve replacement under cardiopulmonary bypass.However,some scholars have questioned the actual clinical effects.The author reviewed the literatures on relevant researches in recent years and conducted a Meta-analysis on 19 literatures,in order to provide some evidence-based medical references for whether IPC is worth promoting in clinical practice.Objective: To evaluate the myocardial protective effect of ischemic preconditioning(IPC)in cardiopulmonary bypass valve surgery by meta analysis.Methods: Two researchers independently searched literatures related to myocardial protective effects of ischemic preconditioning in valve surgery under cardiopulmonary bypass(CPB)in Pubmed,Embase,cnki,wanfang,wip,and chaoxing electronic library by computer.The retrieval time is from the date of database construction to November 2018.The restricted search language be limited as English or Chinese.The retrieval results wereidentified and screened by the above two operators according to the inclusion and exclusion criteria of the literatures.Finally,the inclusion of the literatures was determined through the verification and discussion.Jadad scale was used to evaluate the quality of the included literatures.Read the full text for data extraction.It was decided to use the following indicators as the effect size of perioperative myocardial protection.(1)the level of c-TNT at 3-6h and24 h after surgery,(2)the level of c-TNI at 3-6h and 24 h after surgery,(3)the level of CK-MB at 24 h after surgery,(4)the rate of spontaneous cardiac rebeat during surgery.(5)postoperative mechanical ventilation time;(6)postoperative ICU hospitalization days;(7)length of stay in hospital;Finally,the included literatures were analyzed with Revman5.3software.Results: A total of 19 literatures,including 18 Chinese literatures and 1 English literature,were included through retrieval and screening,all of which were randomized controlled trials,with a total of 1041 patients.The literature quality evaluation scale of Jada was all over 3points.The results of Meta analysis were as follows:Ischemic preconditioning group in the postoperative period of 3 ~ 6 h c-TNI,CK-MB level lower than the control group [SMD =0.73,95% CI(1.11,0.35),P < 0.01;SMD = 0.68,(1.42,0.06),P < 0.01),At the time point of24 h after surgery,c-TNT,c-TNI and CK-MB levels were lower than the control group[SMD=-1.12,95%ci(-1.38,-0.86),P<0.01;SMD=-0.89,95%ci(-1.03,-0.75),P<0.01,SMD=-0.66,95%ci(-0.89,-0.43),P<0.01].The rate of spontaneous heart rebeating was higher than that in the control group [OR=1.84,95%ci(1.19,2.85),P < 0.01].In the postoperative ICU hospitalization days,the ischemic preconditioning group was shorter than the control group[SMD=-0.25,95%CI(-0.42,-0.08),P < 0.05].The results of the Meta-analysis in each group were stable without reversal after the sensitivity analysis by culling literatures one by one.Conclusion:(1)Meta analysis of the 19 references mentioned above showed that ischemic preconditioning can reduce the perioperative myocardial ischemia reperfusioninjury during valve surgery under extracorporeal circulation,improve the rate of spontaneous heart rebeating and shorten the postoperative ICU hospitalization days,it has certain value of perioperative myocardial protection.(2)Whether ischemic preconditioning has long-term clinical value remains further study.(3)This meta-analysis has certain implementation bias,publication bias and has some heterogeneity in some observational indicators.The promotion of ischemic preconditioning in clinical practice should be treated with caution.