Acute myocardial infarction (AMI) is the first cardiovascular cause of death that seriously threatens human health worldwide. Its incidence rate and mortality are increasing year by year and becoming younger. According to statistics, the average age of men and women with AMI for the first time is 65.6 years old and 72 years old respectively, of which 4%~10% AMI occurred before 45 years old. At present, there is no uniform age threshold for young AMI. Generally speaking, AMI with onset age less than 55 years for men and 65 years for women is called early-onset AMI, accounting for 5%~13% of AMI. Compared with elderly patients with AMI, patients with early onset AMI have different risk factors, clinical characteristics and prognosis, such as lower proportion of patients with diabetes and hypertension, more single vessel lesions and rare left main artery involvement, and higher long-term recurrence rate and mortality. Although the progress of preventive measures and treatment methods has reduced the hospitalization rate of elderly AMI patients, the number of young AMI patients in hospital is still rising. Therefore, in-depth analysis of the characteristics of risk factors of early onset AMI and early intervention are of great significance to reduce the risk of onset and improve long-term prognosis.

Hyperlipidemia is an independent risk factor for coronary heart disease at all ages, and is more closely related to early onset AMI. It is reported that more than 50% of early onset AMI patients are accompanied by hyperlipidemia. However, at present, the research on the relationship between blood lipids and early onset AMI is limited to the comparison of the level of single lipid component between early onset AMI and different control groups, or the comparative analysis of the relationship between a specific lipid component and the risk of early onset AMI with young healthy people. There is no research to compare the correlation between various lipid components and the risk of early onset AMI. Therefore, this study plans to deeply analyze the correlation between different blood lipid components and their ratios and early onset AMI, and further analyze which blood lipid indicators are most closely related to early onset AMI through large sample clinical research data, taking late onset AMI patients as the control, which should be paid early attention to and strictly managed.

Inclusion Criteria:

• According to the fourth Universal Definition of Myocardial Infarction (2018), the clinical diagnosis was acute myocardial infarction (AMI), including type 1, 2, 3, 4b and 4c.
• Complete coronary angiography
• Complete biochemical and blood lipid tests

Exclusion Criteria:

• Recurrent AMI
• The onset of AMI exceeds 7 days
• Continuous taking of lipid-lowering drugs ≥ 5 days
• Patients with missing data

AMI patients who completed coronary angiography in the First Affiliated Hospital of Harbin Medical University from September 1, 2021 to September 31, 2022 were included consecutively to establish an AMI research queue. Baseline information such as demographic information, medical history information and laboratory examination results were collected through the electronic medical record system.