Abstract: Objective To explore the effect of different ischemic time on benefit of interventional thrombus aspiration(TA) in patients with acute ST-segment elevation myocardial infarction(STEMI).Methods A total of 198 patients with STEMI who received percutaneous coronary intervention(PCI) were concluded.The 109 patients receiving TA were selected as TA group,and 89 patients who did not reveive TA were selected as control group.Patients were divided into early PCI group[total myocardial ischemia time(TTT)≤4h,72 cases) and non-early PCI group(TTT>4h,126 cases) according to TTT.Epicardial coronary flow was evaluated by myocardial infarction thrombolysis(TIMI) blood flow grading.The effect of TA and TTT on PCI prognosis in patients with STEMI was analyzed.Results The proportion of patients with TIMI blood flow grading 0 in TA group before PCI was higher than that in control group(P＜0.05).The proportion of patients receiving TA in early PCI group was higher than that in nonearly PCI group,while the proportion of patients who occurred major adverse cardiovascular events(MACE) was lower than that in nonearly PCI group(P＜0.05).There was a negative correlation between TA treatment and MACE in patients with STEMI(P＜0.001),while TTT was positively correlated with all-cause death and MACE after PCI(P＜0.001).Logistic regression analysis showed that TTT>4h significantly increased the risk of MACE,and TA treatment reduced the risk of MACE for all STEMI patients(P＜0.05).For the patients in TA group,TTT>4h increased the risk of death and all-cause MACE(P＜0.05).Conclusion For STEMI patients receiving TA treatment during PCI,TTT>4h increases the risk of death and all-cause MACE.

Key words: Different ischemic time, Acute ST-segment elevation myocardial infarction, Interventional thrombus aspiration, Benefit degree