Effects Of Remote Ischemic Preconditioning And Remote Ischemic Postconditioning On Myocardial Injury In Adults Undergoing Valve Replacement Surgery

Objective:The remote ischemic preconditioning (RIPC) and Remote ischemic postconditioning (RPostC) had been also proved their effect in preventing the tissue from IR injury in a large amount of animal experiments and a few clinical trials. However, the clinical applicability of RIPC and RPostC in valve replacement remains to be determined. The present study is aimed to investigate whether left lower limb ischemic preconditioning is beneficial for patients undergoing valve replacement surgery. Another objective of the present study is to observe whether left lower limb ischemic postconditioning is beneficial for patients undergoing valve replacement surgery, and compare the protective of RIPC to RPostC on myocardium I/R injury.Methods:48 adult patients undergoing valve replacement surgery were randomly assigned to three groups:control group (n=16), RIPC group (n=16) and RPostC group (n=16).RIPC consisted of three 5-min cycles of left lower limb ischemia, induced by a manual cuff-inflator placed on the left thigh and inflated 200 mmHg before CPB, with an intervening 5-min reperfusion during which the cuff was deflated. RPostC induced by conditioning three cycles of 5-min of ischemia and reperfusion during the ischemic phase of myocardium.The bypass time, aortic cross-clamping time, the proportion of postoperative sinus rhythm intensive care unit(ICU) length of stay and other clinical data were recorded in three groups. The cTnI, TNF-a and ICAM-1 was measured before surgery and at 0,6 and 24 h after CPB.Results:Three groups of patients in age, weight, cardiopulmonary bypass time, aortic cross-clamp time and preoperative cTnI,TNF-a and ICAM-1 were not significantly different(P>0.05).The cTnI/TNF-a and ICAM-1 of three groups were increased significantly than the basis of value at the point of the end of CPB and 6 hours after CPB.AT the point of the end of CPB, the cTnl, TNF-a and ICAM-1 in RIPC and RPostC were significantly lower than that in control group(P<0.01).6 hours after CPB, the cTnI, TNF-a and ICAM-1 in RIPC and RPostC were lower than that in control group(P<0.05).The cTnI, TNF-a and ICAM-1 of RIPC and RPostC were not different at three time points (P>0.05).Conclusions:The present study demonstrates that adult patients undergoing valve replacement surgery could benefit from RIPC, using transient left lower limb ischemia. The present study also shows that RpostC can reduce the myocardial ischemia-reperfusion injury in adult patients undergoing valve replacement surgery;The RIPC and RPostC provide the same protective effect with respect to reduce postoperative cTnl release.