This study intends to evaluate the characteristics of coronary microcirculatory function in patients with myocardial infarction undergoing reperfusion and its predictive value in assessing cardiac function, myocardial activity, recovery of ventricular wall motion after infarction, and distant myocardial remodeling by cardiac magnetic resonance technique (CMRI). Materials and Methods. The 293 cases of patients with myocardial infarction treated in our hospital from August 2017 to August 2021 were selected as the subjects of this retrospective study, 13 cases were shed due to transfer and moving, and the rest were divided into 140 cases each in the emergency and elective groups according to emergency percutaneous coronary intervention (PCI) and elective PCI. The patients’ myocardial infarct volume ventricular volume, microcirculatory obstruction volume ventricular volume, microcirculatory obstruction volume/myocardial infarct volume, and LVEF, combined with BP and troponin T, were analysed by CMR for comparative analysis, hemodynamic, and cardiac function index differences. Results. The hemodynamics (CO, CI, SV, SI, LVSW1, and LCW) measured at different times were significantly different between the two groups; patients in the emergency group had significantly lower EDV and ESV than the elective group at 7-10 d postoperatively; and EDV, ESV, and LVEF improved in both groups after 3 months, while EDV, ESV, and LVEF improved significantly better in the emergency group than in the elective group, and the difference was statistically significant ( P < 0.05 ). The myocardial infarct quality, VSM score, and ventricular wall motion abnormality score were significantly lower in the emergency group than in the elective group from 7 to 10 d after PCI; myocardial infarct quality, VSM score, and ventricular wall motion abnormality score improved in both groups at 3 months after PCI; and the degree of improvement of myocardial infarct quality and VSM score was significantly better in the emergency group than in the elective group ( P < 0.05 ). Conclusion. Acute myocardial infarction patients with significant effect of emergency PCI treatment can be on their postmyocardial infarction left ventricular function, and in the treatment of coronary heart disease, myocardial infarction diagnosis has a certain reference value.

This study aimed to explore the effects of tissue inhibitor of metalloproteinases‐1 (TIMP‐1) on levocarnitine (LC)-mediated regulation of angiotensin II (AngII)-induced myocardial fibrosis (MF) and its underlying mechanisms. H9C2 cells were treated with AngII for 24 h to induce fibrosis. The cells were then treated with LC or transfected with TIMP‐1-OE plasmid/si‑TIMP‐1. Cell apoptosis, viability, migration, and related gene expression were analyzed. AngII treatment significantly upregulated Axl, α-SMA, and MMP3 expression (P < 0.05) and downregulated STAT4 and TIMP1 expression (P < 0.05) relative to the control levels. After transfection, cells with TIMP-1 overexpression/knockdown were successfully established. Compared with that of the control, AngII significantly inhibited cell viability and cell migration while promoting cell apoptosis (P < 0.05). LC and TIMP-1-OE transfection further suppressed cell viability and migration induced by Ang II and upregulated apoptosis, whereas si-TIMP-1 had the opposite effect. Furthermore, LC and TIMP-1-OE transfection downregulated Axl, AT1R, α-SMA, collagen III, Bcl-2, and MMP3 expression caused by AngII and upregulated caspase 3, p53, and STAT4 expression, whereas si-TIMP-1 had the opposite effect. TIMP-1 is therefore a potential therapeutic target for delaying MF progression.