Objective This study aimed to evaluate the efficacy of early use of PCSK9 inhibitors on serum lipid levels, inflammatory markers, endothelial function, and the incidence of major adverse cardiovascular events (MACE) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Methods We enrolled 80 NSTE-ACS patients treated at the Department of Cardiovascular Medicine, Shanxi Bethune Hospital, from December 2021 to November 2022. Patients were randomized into two groups: the observation group (n=37) received combined therapy of statins and PCSK9 inhibitors, while the control group (n=43) received only statin therapy. Baseline characteristics and venous blood samples were collected to assess lipid profiles, inflammatory markers, and vascular endothelial function indicators. These parameters were re-evaluated after 6 months, and the occurrence of MACE during this period was documented. Results Six months post-treatment, the observation group demonstrated a significant reduction in total cholesterol, triglycerides, and low-density lipoprotein cholesterol compared to their baseline levels. The reduction was more pronounced than that in the control group (all P<0.05). Additionally, the observation group showed a marked decrease in high-sensitivity C-reactive protein and interleukin-6 levels compared to the control group (all P<0.05). Serum endothelin-1 levels in the observation group decreased, while nitric oxide levels increased significantly compared to the control group. During the 6-month follow-up, the observation group exhibited a marginally lower incidence of MACE than the control group (P<0.05). Conclusion Early intervention with PCSK9 inhibitors in NSTE-ACS patients effectively reduces blood lipid concentrations, alleviates inflammatory responses, enhances vascular endothelial function, and lowers the risk of major out-of-hospital adverse cardiovascular events