Thrombus Aspirated From Patients With ST-elevation Myocardial Infarction: Level Of MTORC1 Expressed In Thrombus

Objective:To investigate the relationship between mammalian target of rapamycin complex 1(mTORC1)and intra-coronary thrombosis in ST-segment elevation myocardial infarction(STEMI),and the influencing factors;Besides,to investigate the efficacy and safety of thrombus aspiration(TA)in patients with STEMI.Methods:One hundred and eight patients underwent primary PCI were enrolled from December 2019 to June 2020 in the Affiliated Hospital of Hangzhou Normal University and Second Hospital Affiliated to Dalian Medical University.Finally,Forty-four patients with materials obtained by TA and available for histology analysis(TA group),and sixty-four patients without manual TA(routine PCI group).Meanwhile,Forty-four patients with normal coronary angiography were selected as control group and blood samples were obtained from peripheral artery for thrombus analysis.Collected the basic clinical data,inspection index and the results of coronary angiography,all the patients were followed up for 9 months.The expression of mTORCl in thrombus and peripheral artery blood were assayed by HE staining,western blot and immunohistochemical staining.Results:1.Compared with the routine PCI group,there were less no-reflow or slow flow phenomenon(4.5%vs.18.8%,P<0.05)and a significant increasement in the proportion of sum STR≥ 30%(90.9%vs.75.0%,P<0.05)in TA group.The ejection fraction in TA group improved more obviously when compared with the routine PCI group(8.8±3.6%vs.2.6±6.2%,P<0.05).Notably,decreased stent number(1.1 ±0.3 vs.1.6±0.7,P<0.05)was observed in patients who underwent thrombectomy.And the cumulative survival rates were similar between groups as recorded at different time frames(P<0.05).2.Compared with the control thrombus,the percentage of the expression area of mTORCl in thrombus was significantly increased in patients with STEMI(22.0±6.5%vs.5.7±1.9%,P<0.05).The expression areas of mTORC1 and CD68 were overlaps.The application of western blotting method has revealed the expression of mTORCl in peripheral blood of STEMI patients was significantly higher than control group,P<0.05.3.Correlation analysis showed that the expression of mTORCl related protein in thrombus was positively correlated with age(R=0.557,P<0.05),ischemic time(R=0.540,P<0.05),and hs-CRP(R=0.773,P<0.05);According to the cut-off point of 25%of mTORCl expression area,twenty-two cases had low expression and another twenty-two cases had high expression in observation group,and there was no significant difference in cumulative survival rate between low and high expression cases.Conclusion:1.In patients with STEMI who were undergoing PCI,TA could be considered as a potentially effective therapy,which may result in improving myocardial reperfusion without increasing the risk of MACE events;2.The expression of mTORC1 in coronary thrombus was significantly increased in patients with STEMI;3.The mTORCl was highly expressed in the mononuclear macrophages of the thrombus,which may be involved in initiating STEMI by regulating the function of macrophages.