The Relationship Between Serum Lp (a) Level Concentration And Atherosclerosis In Animal Experiments And Clinical Case Study

Objective:Through the establishment of rabbit atherosclerosis model and retrospective clinical data,our aim is to investigate the relationships between the levels of lipoprotein a(Lp(a))and the severity of artery lesions,and analyze the the relationship among serum Lp(a)level and the severity of coronary artery disease and the short-term prognosis in patients with acute myocardial infarction(AMI)after percutaneous coronary intervention(PCI).Methods:1.Animal experiment: We chose thirty healthy New Zealand white rabbits,ten healthy white rabbits were used as the control group and another twenty white rabbits were fed a high cholesterol diet for eight weeks to establish an atherosclerosis(AS)model.After successful modeling,twenty AS rabbits were randomly divided into two groups: a high cholesterol group(n=10)and a drug intervention group(rapamycin group,n=10).The twenty rabbits continued to be fed with high cholesterol diet for four weeks.Four weeks later,the rabbits were killed and the descending aorta was taken for pathology to evaluate the degree of arterial stenosis.At the end of zero and twelve weeks,the blood samples were collected from middle auricular vein of rabbits in the three groups,and the changes of blood lipids such as Lp(a)were measured by enzymelinked immunosorbent assay((ELISA)).The relationship between the level of Lp(a)and the degree of arterial stenosis was analyzed.2.Clinical data study: Collect 316 AMI patients who were hospitalized for emergency PCI from May 2017 to April 2018 in the Eastern Division of the First Hospital of Jilin University,were selected for emergency PCI treatment.According to the number of coronary artery lesions,they were divided into single-vessel disease group(n = 135),two-vessel disease group(n = 99)and three-vessel disease group(n = 82).According to the Gensini score,there were 79 cases in <38.63 group,79 cases in 38.63-56.25 group,79 cases in 56.25.-83.00 group,and 79 cases in >83.00 group.The patients’ general data,biochemical parameters,echocardiography results,and coronary angiography findings were recorded,and the major adverse cardiovascular events(MACE)were also recorded for a 12-month follow-up.The relationships between the risk factors and the number of diseased branches,Gensini scores and the recent MACE were analyzed.The receiver operating characteristic(ROC)curve was drawn to investigate the values of Lp(a)to predict the recent occurrence of MACE in the patients with AMI.Results:1.Animal experiment: Compared with the control group,the serum levels of Lp(a),TC,TG,LDL-C and HDL-C in rabbits of the high cholesterol group were significantly increased,and the difference was statistically significant(P <0.05).Compared with the high cholesterol group,the serum levels of Lp(a),TC and LDL-C in the rabbits of the drug intervention group were significantly decreased significantly,and the difference was statistically significant(P <0.05).The aortic pathological results of rabbit among the three groups showed that the rabbits in high cholesterol group had the most severe atherosclerosis.The high cholesterol group show a large amount of lipid particles deposition and HE staining shows a lot of foam cells.Comparing the drug intervention group with the high cholesterol group,the degree of foaming in the aorta was significantly relieved,and the degree of atherosclerosis is reduced.In the control group,no lipid deposition is observed in the aorta of the control group,and the HE stained cells are arranged neatly without foam cells.2.Clinical data study: The serum Lp(a)concentration in three-vessel disease group was higher than that in single-vessel disease group(P <0.05).But there was no statistical difference between the three-vessel disease group and the double-vessel disease group and the comparison between the single-vessel disease group and the double-vessel disease group.The significance was significant(P> 0.05).The serum Lp(a)concentration in > 83 group was significantly higher than that in < 38.63 group(P <0.05).There was no significant difference among other groups.According to the results of Spearman correlation analysis,there was a positive correlation between serum Lp(a)concentration and the number of coronary lesions or the Gensini score of coronary artery lesions(r = 0.144,P = 0.010),(r = 0.164,P = 0.003).After adjusting for age,male proportion and smoking,serum Lp(a)(OR=1.005,95%CI1-1.011,P=0.046)、serum NT-pro BNP(OR=1.702,95%CI1.001-2.902,P < 0.001)and ejection fraction(OR=0.899,95%CI0.852-0.948,P < 0.001)were independent predictors of recent MACE occurrence in AMI patients.The ROC curve showed that the concentration has a strong predictive ability that the level of serum Lp(a)predict the recent occurrence of MACE in AMI patients.Taking the serum Lp(a)concentration > 76.89mg/L as the critical value,the prediction sensitivity was 61.3% and the specificity was 55.7%.Conclusion:1.Through the rabbit atherosclerosis model,we found that high levels of serum Lp(a)are involved in the formation of atherosclerosis.Serum Lp(a)levels are related to the severity of atherosclerotic lesions.The higher the level is,the more severe the severity of atherosclerotic lesions are.2.The level of Serum Lp(a)can reflect the severity of coronary artery disease in patients with AMI,which has a positive correlation with the severity of coronary artery disease.The higher the serum Lp(a)level is,the more severe the coronary artery disease are.3.Serum Lp(a)level is an independent predictor of recent MACE in patients with AMI.