Clinical Research Of Ischemia Modified Albumin In The Early Diagnosis And Risk Stratification In Acute Coronary Syndrome

PrefaceThe main pathogenesis of acute coronary syndrome(ACS)is the rupture or damage of instability atheromatous plaque,leading to completely or incompletely thrombosis.This produces progressive tissue ischemia which may progress to cardiomyocyte necrosis and subsequent cardiac remodelling.It is urgent to develop a heart biomarker with higher sensitivity to help physicians to detect myocardial ischemia before the formation of myocardiolysis in the early diagnosis of ACS. Ischemia modified albumin(IMA)is the first heart biomarker approved by US FDA for diagnosis of myocardial ischemia,which can be detected by The Albumin Cobalt Binding test(ACB test).Many foreign researches has confirmed that IMA has high sensitivity in the early diagnosis of myocardial ischemia among the patients of ACS.The objective of this study is to investigate the significance of IMA in the early diagnosis and the risk stratification of ACS by domestic kit and automatic biochemical analyzer,providing theoretical evidences for clinical practice.Materials and Methods1.Subjects(1)Patients:Patients with acute chest pain suspected of ACS,who was received by emergency department or cardiology department in Shengjing Hospital from April 2007 to October 2007.(2)Final diagnosis and group:①unstable angina pectoris:26 patients including 15 men and 11 women with a mean age of(63±12)years. ②acute myocardial infarction:53 patients including 39 men and 14 women with a mean age of(65.75±11)years.③Non-ischemia chest pain:38 patients including 26 men and 12 women with a mean age of(53±9)years.④Healthy controls:30 patients including 22 men and 8 women with a mean age of(59±10)years from out-patient medical examination.2.Research methods(1)Sample collection:Collects 6ml of blood through median cubital vein of all the patients after 30 min admitted by the emergency,among which 4 ml were used to directly measure BNP and cTnI,while the remaining 2 ml were centrifuged to collect serum stored with the temperature- 20℃,prepared for IMA measurement.(2)Detection methods:①Measurement of IMA:By the estimation of albumin cobalt binding assay, provided from Changsha Yikang Technology development Ltd,Co.②Measurement of cTnI:By chemiluminescence detection method,provided from US BECKMAN Co.To test results in the Un Access Immunoassay Instrument of US BECKMAN Co.(3)Observation indexes:①IMA levels among groups,that is ACB value.②Left ventricle ejection fraction of all patients selected were measured within 1 week.Evaluating cardiac function of AMI patients.③AMI patients were followed up for 3 months to record cardiac death events.3.Statistical analysisAll the data were processed by SPSS12.0 softwares.Measurement data was expressed by means of(?)±s.Single factor ANOVA or t-test to test interclass difference.The numeration data were compared by Chi square test.Peason related test was used to analyze the relationship between IMA levels and LVEF.The correlation of cardiac death events was analyzed by Logistic regression model.If P value was less than 0.05,the difference was considered statistically significant.Results1.IMA levels among groups and Comparison of diagnosis efficacy(1)ACB valus of ACS(54.73±6.36 U/ml)was significantly less than that of NICP and healthy control group,P＜0.001.(2)At a cutoff value =63.80 U/ml,the area under the ROC curve was 0.875, Sensitivity and specificity were 86%and 47%.(3)The sensitivity and the negative predictive value of IMA was significently higher than that of ECG and cTnI.When IMA was used in combination,the sensitivity and the negative predictive value were significantly greater than that used alone.2.Comparison of IMA levels between heart failure group and non-heart failure groupACB value of acute heart failure group was significantly less than that of nonheart failure group,having significant difference P＜0.05.ACB value was positively correlated with LVEF by Peason related test,r=0.619,P＜0.001.3.Comparison of IMA levels between death group and survival group(1)ACB valus of death group was significantly less than that of survival group,P＜0.05.Among death cases,4 died from cardiogenic shock,3 died from progressive left ventricular systolic dysfunction,2 died from sudden death.(2)At a cutoff value =50.84U/ml,the area under the ROC curve was 0.826, Sensitivity and specificity were 78%and 82%.(3)With death events as the dependent variable,and gender,age,smoking, hypertension,diabetes mellitus,hyperlipoidemia,cardiac function,ACB value,and BNP value as independent variables,all the case was processed by Logistic regression analysis with the results that the depression of ACB value was an independent risk factor of cadiac death events,OR value was 0.724,P=0.046.Conclusion1.IMA can be used in the early diagnosis of ACS among the suspect patient with chest pain. 2.The level of IMA may have correiation to the LVEF.3.IMA can be used as independent risk factor of death in short term among the AMI patient.