For patients with anterior ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI), whether early application of proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors to rapidly reduce low-density lipoprotein cholesterol (LDL-C) before PCI could effectively inhibit left ventricular remodeling has been rarely reported. The aim of this study was to investigate the effect of early application of PCSK9 inhibitors Evolocumab to rapidly reduce LDL-C levels before primary PCI treatment on left ventricular remodeling in STEMI patients. Eligible patients were randomly randomized 1:1:1 to one of the following three groups immediately after enrollment: (1) Intensive statin group: rosuvastatin 20 mg per day, in addition to usual therapy; (2) Combined intensive statin and PCSK9 inhibitor group: rosuvastatin 20 mg per day and subcutaneous injection of evolocumab 140 mg twice a month, for at least 3 months, and preferably 6 months; (3) PCSK9 inhibitor alone group: subcutaneous injection of evolocumab 140 mg, twice a month for at least 3 months and preferably 6 months.