A Clinical Study On The Characteristics Between Cardiovascular Risk Factors And Severity Of Coronary Artery In Patients With Non-ST Segment Elevated Myocardial Infarction

According to the latest investigation data for the Coronary Artery Disease (CAD) in China on the beginning of 21th century,the morbidity and the mortality of CAD are both presenting the ascending tendency.Nowadays,CAD has become one of the most common cardiovascular diseases in China, especially in the urban areas.CAD is the universal cause for clinical treatment among the middle-elderlypopulation.Acute Coronary Syndrome(ACS),which features of acute onset,is a certain class of CAD.ACS includes Unstable Angina(UA),Acute Myocardial Infarction(AMI) and sudden death.Based on the changes of ST-segment on electrocardiogram,AMI can be divided into two categories:ST-Segment Elevated Myocardial Infarction(STEMI) and Non-ST-Segment Elevated Myocardial Infarction(NSTEMI).There's direct relationship between the incidence of ACS and the unstable plaque.However,more and more evidence-based medical trials show that it's impossible to find the unified regime for different kinds of ACS.At present,medical studies recognize that the rupture of unstable plaque in STEMI patients leads to thrombosis,which clogs the coronary vessel.As a result,the principle of refusing treatment in STEMI is to make the infarction related artery unblocked.In other words,the optimal strategy for STEMI is Primary Percutaneous Coronary Intervention(PCI) or thrombolytic therapy as soon as possible.On the contrary,concerning to the clinical features and the treatment regimes of NSTEMI,people haven't reached to the consensus.Besides,with the further study on the risk factors of cardiovascular diseases,there're more than 200 kinds of risk factors resulting in the atherosclerosis,and some new elements that may influence the process of plaque formation are being studied.Heretofore,the definitive risk factors which lead to the ascending tendency of CAD are as follows:the increasing population of old people,the Significant elevation of morbidity and prevalence on hypertension and Diabetes Mellitus,the inappropriate dietary pattern,the growth on the Body Mass Index(BMI),the abnormality of the serum lipid and the increasing number of smokers.Nevertheless,the independent factors leading to the incidence of NSTMI haven't officially confirmed,and the relationship between these risk factors and the severity of coronary artery in NSTEMI haven't reached to the agreement.Under the above circumstances,the objective of this study is to investigate the correlation between multiple cardiovascular risk factors and the coronary angiographic features in patients with NSTEMI,the aim of which is to prevent NSTEMI more efficiently and guide the treatment more reasonably.83 patients diagnosed to AMI by coronary artery angiography in the First Hospital of JiLin University between January and December in 2008 are chosen as our objects in this study.Based on the changes of ST-segment on electrocardiogram,they're divided into two categories:33 cases for STEMI and 50 cases for NSTEMI.All the patients were admitted to hospital and received primary PCI in the first 12 hours after the acute onset of AMI,then the results of angiography were judged by the professional interventional radiologists,and the optimal strategies were selected on the basis of severity of coronary artery.In the NSTEMI group,19 persons are male,the other are female,the average age is 60.97±12.90,and the average BMI is 25.43±2.90,smoking exits in 15 patients, hypertension exits in 22 patients,DM exists in 6 patients,and abnormal blood fat exits in 26 patients.We totally investigated 132 branches of coronary arteries in NSTEMI group,and 85 branches are infarction related arteries(IRA) which the area of stenotic segment is more than 50%.The distributions of the IRA include 5 branches in LM,28 branches in LAD,27 branches in LCX and 25 branches in RCA.In other words,three-vessel lesion case exists in 20 patients and single vessel lesion case in 6 patients.The independent T-test shows that there are more diffused lesions in NSTEMI group than in STEMI group, especially the percentage of the three-vessel lesion cases(20/33,60.6%vs 18/50, 36%P=0.028).It is suggested that the severe stenosis,whose degrees were between 90%to 99%,make significant differences between the two groups (32/99,32.3%vs 19/150,12.7%P=0.00).Moreover,the left circumflex artery gets more chances to be involved in the NSTEMI group.According to the Gensini score and the numbers of IRA,the severity of coronary artery is valued, than single factor analysis and multivariate analysis are both calculated by SPSS 10.0 software.The single factor analysis implied that aging,male and the history of hypertension were all associated with increases in severity of coronary artery and the number of coronary lesions(r=0.379～0.495,P=0.0003～0.007).On the other hand,the diastolic blood pressure madethe decrease tendency(r=-0.369, P=0.038).Multivariate logistic regression analysis indicated that gender is the independent predictive factor for the severity of the coronary artery(B=48.508, P=0.014),therefore,male is apt to have NSTEMI.Up to now,many scholars only use the method of single factor analysis but not the multivariate analysis when they study the correlation between cardiovascular risk factors and the severity of coronary artery.Comparatively,our study uses both the single and the multivariate analysis to discuss the problem.The statistic outcomes of the two methods aren't completely same,the cause of this phenomenon is that the multivariate analYsis takes the mutual interferences and the compound effect of all the risk factors into account,therefore the results of the multivariate analysis are more credible.In addition,the number of the clinical sample is so limit that larger scale clinical observation should be carried on in future.Finally,we draw the conclusion that multiply-vessel lesion and the severe stenosis can be best identified by the feature of coronary angiography in the NSTEMI patients.Male is the independent predictor of the severity of coronary artery for NSTEMI patients.Aging and the history of hypertension are associated with the severity of the coronary artery.What's more,as advanced age and gender are uncontrollable factors,the abnormal blood pressure level must be decreased to the normal level.We should pay more attention to hypertension in order to prevent NSTEMI.