Objective: To observe the expression and clinical significance of serum homocysteine (Hcy), Cystatin C (CysC), matrix metalloproteinase-1 (MMP-1), neutrophil gelatinase related lipid delivery protein (NGAL) in patients with acute myocardial infarction (AMI) after PCI. Methods: 70 patients with AMI in our hospital were selected from March 2018 to September 2020. According to whether ventricular remodeling occurred after PCI, they were divided into no ventricular remodeling group(n=49) and ventricular remodeling group (n=21). The serum MMP-1, Hcy, NGAL, CysC levels and cardiac function indexes [left ventricular posterior wall thickness (LVPWT), left ventricular end diastolic diameter (LVEDD), left ventricular ejection fraction(LVEF), ventricular septal thickness (IVST)] of patients were detected. The correlation between serum MMP-1, Hcy, NGAL and CysC levels and cardiac function indexes were analyzed. The influencing factors of ventricular remodeling after PCI in patients with AMI were analyzed. Results: The serum MMP-1, Hcy, NGAL and CysC levels in the ventricular remodeling group were higher than those in the no ventricular remodeling group P<0.05, while LVEDD, IVST and LVPWT were all greater than those in the no ventricular remodeling group, and LVEF was smaller than that in the no ventricular remodeling group (P<0.05). Pearson correlation analysis results showed that serum MMP-1, Hcy, NGAL, CysC levels were positively correlated with LVEDD, IVST and LVPWT, but negatively correlated with LVEF (P<0.05). Univariate analysis showed that there were statistically significant differences in infarct site, arrhythmia, monocyte (MO), creatine kinase isoenzyme (CK-MB), and time from onset to opening of infarct-related artery between the two groups (P<0.05). Multivariate Logistic regression analysis showed that anterior wall infarction site, arrhythmia occurs and high levels of MO, CK-MB, MMP-1, Hcy and CysC were all risk factors for ventricular remodeling after PCI in patients with AMI (P<0.05). Conclusion: The serum expressions of MMP-1, Hcy, NGAL and CysC are closely related to ventricular remodeling in patients with AMI after PCI. The detection of the above indexes can provide some reference for the prediction and prevention of ventricular remodeling in patients with AMI after PCI. [ABSTRACT FROM AUTHOR]