Abstract: ［Abstract］Objective〖HTSS〗To observe the effect of deferred stent implantation in acute ST-segment elevation myocardial infarction(STEMI) patients with high thrombus burden and diffuse lesion.
 〖WTHZ〗Methods〖HTSS〗The 96 STEMI patients were selected for coronary angiography to show severe thrombus load and diffuse lesions of infarct related artery(IRA). After initial intervention, the thrombolysis in myocardial infarction（TIMI）blood flow grade 3 of the infarct related artery(IRA) was restored, but the lesions were diffuse. They were randomly divided into immediate group(n=47) and deferred group(n=46). The immediate group received the follow-up stent implantation, and the deferred group received stent implantation 1 week later. The incidence of no re-flow/slow flow, the average number of stents per capita, the average length of the stents, the average length of stay and the mean hospitalized cost were compared between two groups. Left ventricular ejection fraction(LVEF), left ventricular end diastolic diameter(LVD) and major adverse cardiovascular events(MACE) were compared at 6 months.
 〖WTHZ〗Results〖HTSS〗The incidence of no re-flow/slow flow in deferred group was significantly lower than that in immediate group, the number of stent implantation per capita and the average stent length were lower than those in immediate group, and the proportion of stent free implantation was higher than that in immediate group（P＜0.05）. After 6 months, compared with the admission, LVEF and LVD of the two groups were significantly higher and lower(P＜0.05). At 6 months, compared with the immediate group, the deferred group had higher LVEF and lower LVD(P＜0.05). The average length of stay in the deferred group was longer than that in the immediate group, and the average cost of stay was less(P＜0.05). After 6 months follow-up, there was no significant difference in cardiovascular death and target vessel revascularization(TVR) between two groups(P＞0.05). The cumulative MACE free survival rate in deferred group was significantly higher than that in immediate group(P＜0.05).
 〖WTHZ〗Conclusion〖HTSS〗For STEMI patients with high thrombus burden and diffuse lesion, deferred stent implantation can reduce the incidence of no-reflow/slow flow, reduce the number of stent implantation, improve cardiac function and ventricular remodeling at 6 months, reduce the readmission rate within 6 months, and reduce medical costs.

Key words: myocardial infarction； high thrombus burden, stents