The Study Of Leukocyte Telomere Length On Adverse Prediction In Patients With Coronary Artery Disease

Background:Coronary Heart Disease(CHD)is a kind of disease caused by stenosis or occlusion of the coronary arteries,leading to the myocardial ischemia or myocardial necrosis,which has high morbidity,disability and mortality.Therefore,it is of great significance for the coronary heart disease patients to take risk stratification in time and take appropriate treatment measures.Telomere is a small DNA-protein complex at the end of chromosomes which is present in eukaryotic cells and contains a DNA repeat segement of(TTA GGG).It plays a very important role in maintaining chromosome stability and cell mitosis,and gradually shortens as cell division procces dincreases,which is called the molecular "biological clock".Leukocyte Telomere Lengths(LTLs)shortening has been found to be associated with a variety of diseases,such as blood disorders,tumors,endocrine diseases,and cerebrovascular diseases.Percutaneous Coronary Intervention(PCI)has become more and more common in the assessment of coronary severity.Coronary arteriograghy(CAG),as the gold standard,has been considered to determine the severity of coronary stenosis,but it is obviously insufficient in the assessment of severity of coronary artery disease,due to its high medical expenses and intraoperative risks.Therefore,it is important to find a relatively safe and non-invasive method to predict the severity of coronary lesions and carry out risk stratification timely and accurately.With the in-depth study of the clinical value of LTL,it has been found that the LTL is generally shortened in patients with CHD,and LTL shortening is more serious in patients with myocardial infarction.Therefore,we hypothesize that the severity of coronary atherosclerosis is related to LTL.LTL can be used for predicting the severity and prognosis in patients with CHD.However,the current research is mostly for the study of foreign white human patients.Whether LTL has the same value for the risk stratification and prognosis in chinese patients with CHD is still uncertain.Objective:The present study is aimed to determine the changes of LTL and to explore the predictive value of LTL in the risk stratification and prognosis in patients with CHD.Methods:1.The present study recruited patients who were admitted to the Department of Cardiology of Liaocheng People’s Hospital from October 2017 to April 2018.After examination of electrocardiogram and coronary angiography,patients the CHD were divided into 3 sub-groups according to the diagnostic criteria: SAP(stable angina pectoris)group,UAP(unstable angina pectoris)group and AMI(acute myocardial infarction)group,age,gender,ethnicity matched and Non-CHD patients who had a normal coronary artery diagnosed by coronary angiography were chosen as the NC(normal control)group;2.After admission,the releted examinations were completed.2 ml fasting venous blood was taken on the day of CAG,DNA purity and concentration were extracted and detected(ultraviolet absorption spectrum was between 260-280 nm),and the LTLs was measured by Real-Time PCR methods,using 36B4 as the internal reference,LTL in CHD group and control group were detected;3.According to the severity of stenosis and the number of diseased vessels,the severity of coronary artery was determined according to the Gensini score;4.Exploring the value of LTL for risk stratification in patients with CHD;5.Followed up within 6 months of patients discharging from the hospital,MACEs(Major Adverse Cardiovascular Events)were recorded,MACEs including heart failure,reinfarction,cardiogenic shock,death,and readmission.According to the median value of LTL,the patients were divided into two groups,and the ratio of MACEs events in the two groups is compared.The ROC curve was constructed to assess the predictive power of LTL for MACEs.COX regression analysis was used to evaluate the association between LTL and MACEs.EFS(Event-free survival)present were compared for long LTL and short LTL using a Kaplan-Meier curve.Results:1.Patients with CHD(coronary heart disease)were divided into 3 subgroups: SAP group(n=98),UAP group(n=144)and AMI group(n=124),and NC group(n=30)were selected as controls.,2.The length of LTL group in patients with SAP group(0.80±0.12),UAP group(0.78±0.19)and AMI group(0.76±0.14)was significantly shorter than that of NC group(1.17±0.27)(p<0.05).3.The older patients in the NC group(r=-0.320,p<0.05)and the CHD group(r=-0.169,p>0.05),has the shorter the LTL.4.The CHD group patients with,higher the Gensini score of have the shorter the LTL(p<0.05,).5.In the AMI group(48.32±29.08),the Gensini score was higher than that of the UAP group(21.74±22.20)and that of the SAP group(16.01±14.42),(p<0.05).6.The rate of MACEs,in the short LTL group was 1.59 times than that of the long LTL group(p<0.05),and the risk of heart failure in the short LTL group was 5.57 times than that of the long LTL group(p<0.05).7.The ROC curve showes that the area under the curve of LTL for MACEs prediction was 0.73,with a sensitivity of 52% and a specificity of 86%.8.COX regression analysis shows that LTL in CHD patients is an independent risk factor for predicting MACEs(P<0.05).9.The K-M survival curve shows that the EFS in the long LTL group was higher than that of the short LTL group.Conclusion:1.LTL is related to the severity of CHD and ages.The shorter of LTL,the severer in the CHD and older of ages.It is suggests that LTL can be used to predict the severity of CHD.2.The shorter of LTL,the higher prevalue of MACEs in patients with CHD,It is showed that LTL can be used in the prediction of MACEs,that is,LTL can be used as a parement in the risk stratification and prognosis in patients with CHD.