Diabetes is a leading social and economic burden in the world. It is the main reason of macrovascular disease incidence and mortality. Prospective studies have demonstrated that high glycosylated hemoglobin (HbA1C) levels are associated with an increased risk of cardiovascular events in a population of diabetic patients without a history of coronary artery disease. Further, the predictive value of high preprocedural glycemia levels has been reported in diabetic patients undergoing percutaneous coronary intervention (PCI). The aim of the present study was to assess the predictive value of preprocedural HbA1C levels for cardiovascular complications in a large population of diabetic patients undergoing PCI with stent implantation. Glycosylated hemoglobin (HbA1c) reflects the average blood sugar level in the past 2-3 months. As glycosylated hemoglobin has been clinically tested and standardized internationally, increasing evidence is recommended for routine monitoring in diabetes care. The American Diabetes Association (ADA) suggested that in the treatment of diabetes, blood sugar control should control HbA1c level below 6.5%. Although，there is evidence that controlling blood glucose can reduce the incidence of microvascular complications, in the past three trials, intensive glycemic control did not significantly reduce adverse CV events in patients with onger duration of diabetes.Therefore, most primary and secondary prevention guidelines recommend HbA1c below 6.5% or 7% to prevent adverse cardiovascular outcomes in patients with diabetes mellitus. The optimal target level of glycosylated hemoglobin is still hotly debated. In addition, there is still lack of evidence for the level of HbA1c in patients with major vascular disease history in secondary prevention of recurrence cardiovascular events.

Therefore, to explore and determine the optimal level of blood glucose control is the focus of controversy in preventing recurrence cardiovascular events in diabetic patients. Investigator will combine epidemiology and metabolomics to study the effect of glycosylated hemoglobin on secondary cardiovascular events, and further determine whether to strengthen hypoglycemic treatment after PCI.

This is a longitudinal cohort study including retrospective study, prospective study and nested case-control study.The first cross-sectional survey was conducted in 2021.

Inclusion Criteria:

- 1. Age ≥ 18, male or female;

2. all patients with diabetes combined with PCI operation;

Exclusion Criteria:

• 1. Less than 18 years old

  2. Pregnancy

  3. Patients with preoperative glycosylated hemoglobin index deficiency

  4. Chronic maintenance hemodialysis patients

Demographic data, cardiovascular examinations and laboratory parameters were collected from 1500 hospitalized diabetic patients with PCI. Patients younger than 18 years old, pregnant, preoperative HbA1c deletion and chronic maintenance hemodialysis were excluded. According to ADA and AHA guidelines and predetermined glycosylated hemoglobin values, based on clinical relevance, especially glycosylated hemoglobin < 6.5%, 6.5% ≤ glycosylated hemoglobin ≤ 7.0%, glycosylated hemoglobin > 7.0%, and statistical end events including patients with more than or equal to two PCI enents, patients with all-cause motality and cardiac motality.Through prospective cohort study and nested case-control study,analysis related risk factors and metabolomics molecular differences between revascularization patients and non-revascularization patients.The instrument platforms of gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are used to metabonomic analysis.