Effects Of Remote Ischemic Preconditioning On Coronary Blood Flow

BACKGROUND:At present,reperfusion therapy is the main clinical treatment for severe myocardial ischemia in patients with coronary heart disease.However,after the opening of pathological vessels,reperfusion injury will inevitably occur in the ischemic part of the myocardium,which will further aggravate the myocardial injury and affect the reperfusion effect and prognosis.In some economically underdeveloped areas,patients before receiving professional intervention is likely to tolerate longer and myocardial ischemic lesions is heavier,even in the acute myocardial ischemic events occur not reperfusion therapy in time,missed the best time of myocardial salvage window,make the effect of reperfusion therapy,so the extra need a cheap,This convenient and fast method can provide myocardial protection for patients with myocardial ischemia,making the effect of reperfusion therapy more significant.Remote Ischemic Preconditioning,often referred to as RIC or RIPC,occurs when a part of the body,such as the upper limb,is subjected to transient,reversible Ischemic hypoxia.Induced by ischemic organs other organs(such as heart,brain,liver,kidney)for subsequent severe or fatal ischemic anoxia protection,but the mechanism still is not very clear,always,always many clinical studies have shown that acute myocardial ischemia occurs,the application of RIPC can reduce acute myocardial ischemia,myocardial infarction area,In addition,perioperative and preoperative application of RIPC can increase coronary blood flow,reduce troponin release during CABG and PCI,and reduce myocardial injury.We explored the effects of RIPC on coronary hemodynamics through imaging and serological indicators,which is conducive to the evidence support and mechanism study of clinical application of RIPC、Objective:To determine the effect of short-term remote ischemic preconditioning(RIPC)on coronary blood flow and microcirculation function using the quantitative flow ratio(QFR)and index of microcirculatory resistance(IMR).Discuss the clinical significance of RIPC.Methods:Patients undergoing coronary angiography(CAG)were randomized to RIPC or control group.After the first CAG,patients meeting the inclusion criteria were further randomly divided into unilateral upper limb(UL)or lower limb(LL)groups,in which RIPC group underwent 4 cycles of ischemia/reperfusion cycle,and control group underwent virtual RIPC.And then we did the second CAG.CQFR was measured after each CAG and CQFR-FQFR and IMR were calculated and compared in patients with cardiac syndrome X.Before each angiography,arterial blood was extracted and centrifuged to separate the plasma,which was immediately stored in a refrigerator at-80℃.Uniformly analyze samples using ELISA。Results:We measured 253 coronary arteries in 129 patients.Compared with the control group,the average c QFR of the RIPC group increased significantly after RIPC(P<0.001).Additionally,23 patients with cardiac syndrome X(IMR > 30)were included in this study.Compared with the control group,IMR(P<0.001)and the difference between c QFR and f QFR(c QFR-f QFR)(P<0.001)both decreased significantly after receiving RIPC.We collected blood samples from 91 patients in the ascending aorta before and after coronary angiography,45 in the experimental group and 46 in the control group.It was found that the concentration of ET-1 in the RIPC group decreased during the second time compared with the first time(P<0.001)while bradykinin increased(P<0.001),no significant change in nitric oxide(P<0.001),no significant changes in the two measurements of the control group Variety.Conclusion:RIPC can improve the c QFR of target vessels in patients with coronary heart disease,improve microcirculation in patients with cardiac syndrome X,increase the level of BK,and decrease the level of ET-1.