Correlation Of Lipoprotein(a) With The Risk And Severity Of Coronary Artery Disease

BackgroundAtherosclerotic vascular disease(ASCVD),especially coronary artery disease(CAD)and myocardial infarction,is the leading cause and financial burden in the whole word.Atherosclerosis(AS)is the common pathophysiology of ASCVD,which involves vascular endothelial injury,abnormal lipid metabolism and chronic inflammatory response,causing arterial plaque formation and progressive stenosis of the lumen,which may eventually lead to the occurrence of major adverse cardiacvascular events resulting from plaque rupture.There is still the risk of coronary artery disease in spite of controlling traditional risk factors.Therefore,domestic and foreign studies have paid close attention to more risk factors of atherosclerosis recently.Current epidemiological and clinical studies have shown that lipoprotein(a)(Lp[a])is closely related to cardiovascular disease(CVD).According to an epidemiological survey of 2018,there are about 1.43 billion people in the world with serum Lp(a)levels exceeding 50 mg/dL,and this proportion is estimated to be 10%in most Asian populations including China,whose risk of ASCVD is higher.Lp(a)is a low-density lipoprotein-like particle,which composed of its specific glycoprotein apolipoprotein(a)(Apo[a])and apolipoprotein B covalently bonded by disulfide bonds.Lp(a)can increase lipid deposition on the arterial wall,promote the formation of foam cells,increase the production of oxidative free radicals in monocytes,promote the proliferation of smooth muscle cells,and incerese the chemotactic activity of endothelial cells under the endothelium.Therefore,the correlation between lipoprotein(a)and the risk of cardiovascular disease is receiving increasing attention.Prospective studies of Lp(a)in general population and familial hypercholesterolemia have shown that patients with higher levels of serum Lp(a)have a higher risk of CVD.In addition,coronary artery disease patients with high level of Lp(a)were found an elevated risk of recurrent myocardial infarction and death than the low.However,the results of the relevant studies are not consistent.Some studies indicate elevated Lp(a)do not increase CVD risk when low-density lipoprotein cholesterol(LDL-C)level is well-controlled.And meta-analysis about secondary prevention in Lp(a)has different risk ratios for coronary artery disease.Therefore,whether Lp(a)is an independent risk factor and residual risk of CVD has no clear answer at home and abroad.Moreover,current studies have not confirmed the serum Lp(a)level and the severity of CAD and the degree of coronary stenosis.Therefore,this study intends to analyze the predictive value of Lp(a)in CAD and coronary stenosis.Objective1.To compare the relationship between different serum Lp(a)levels and the risk of suffering coronary artery disease in patients with coronary angiography,and to explore whether Lp(a)is an independent risk factor for CAD;2.To compare the differences in CAD risk between different Lp(a)under similar low-density lipoprotein cholesterol level,and to explore whether Lp(a)is the residual risk of CVD;3.To explore the relationship between different clinical stability and Lp(a)levels in patients with coronary artery disease;4.To analyze the relationship between Lp(a)and coronary Gensini scores in patients with coronary heart disease,and to explore the relationship between Lp(a)and coronary stenosis.Methods and resultsPart I Clinical value of serum Lp(a)level and risk of coronary artery disease in patients with coronary angiographyIn this study,a retrospective cohort study was conducted to collect 531 inpatients who underwent a visit to the Nanfang Hospital from January 1,2013 to December 31,2016.They were all underwent eight tests for serum lipids and performed coronary angiography.The data of serum Lp(a)in all patients were counted by reviewing the original medical records and recording them in the form of a questionnaire.Patients were divided into high lipoprotein(a)group and low lipoprote:in(a)group,according to whether Lp(a)was>30 mg/dL.The general clinical data,other blood lipid indexes,liver and kidney function,C-reactiv protein levels were compared between the two groups.According to the results of coronary angiography,the relationship between serum Lp(a)level and risk of coronary artery disease was analyzed.The study found that there was no significant difference in age,gender,body mass index,smoking,hypertension and diabetes history between high Lp(a)group and low Lp(a)group(P>0.05),which was of comparability.One-way logistic regression analysis showed that age,gender,smoking and diabetes history,glycosylated hemoglobin,creatinine,C-reactive protein,high-density lipoprotein cholesterol,apolipoprotein A-I and Lp(a)were risk factors for coronary artery disease.Multivariate Logisitic regression analysis showed that age,gender,LDL-C and Lp(a)were independent risk factors for CAD in the enrolled population.Patients with elevated Lp(a)suffer higher risk of CAD(OR=2.443,95%CI:1.205?4.951,P=0.013).Regardless of the level of LDL-C,the risk of CAD was higher in the high Lp(a)group than the low(P=0.006 and P=0.020).Part ? Relationship between serum Lp(a)level and clinical stability and severity of coronary artery stenosis in patients with coronary artery diseaseThis study retrospectively collected 439 patients with coronary artery disease diagnosed by coronary angiography from January 1,2013 to December 31,2016 in Nanfang Hospital.According to clinical symptoms,the patients were divided into acute coronary syndrome(ACS)group and stable angina pectoris(SAP)group.The general clinical data,Lp(a)level and other blood lipid indexes,liver and kidney function and C-reactive protein were compared between the two groups,to assess the relationship between Lp(a)levels and clinical stability in patients with coronary artery disease.Gensini score was compared between high and low Lp(a)group according to coronary angiography.The cut-off value of the Gensini score was calculated according to the ROC curve of the patient's Lp(a)and Gensini scores,which divided the patients into the high Gensini score group(HGS)and the low Gensini score group(LGS).The proportion of high Gensini Score in each group were analyzed,to explore the relationship between Lp(a)and the degree of coronary stenosis.The study found that in patients with coronary artery disease,the ACS group had higher Lp(a)level than the SAP group(P<0.001).The Gensini scores of high and low Lp(a)group were 52.35±34.58 and 44.26±26.98(P=0.010).The cut-off value of Gensini score was 85 according to the ROC curve.And patients with high Gensini score between the two groups accounted for 17.3%and 5.6%,respectively(P=0.026).Correlation analysis showed a linear relationship between Gensini score and Lp(a)in patients with coronary artery disease(R=0.130,?=0.142,95%CI:0.040?0.244,P=0.006).ConclusionThis study confirmed that Lp(a)is an independent risk factor for CAD.Patients with high serum Lp(a)levels have an increased risk of CAD,and Lp(a)is a residual risk of CAD.In patients with CAD,elevated serum Lp(a)is associated with the clinical stability and the degree of coronary stenosis.Lp(a)in patients with ACS is higher than SAP group.The higher the level of Lp(a),the more severe the degree of coronary stenosis.