The Prognostic Value Of Plasma B-natriuretic Peptide With Acute Myocardial Infarction In Basic And Clinical Research

Objective The activation of neuroendocrine system and cytokine after acute myocardial infarction (AMI) is a widespread pathological phenomenon which plays an important role in the process of CHF.Prepare the experimental rat model of CHF after MI and observe the changes of BNP、ET-1、IL-1β、AngⅡ、TNF-α and the BNP mRNA and TNF-a mRNA expression in non-infarcted myocardial tissue.Explore the relationship between CHF and this indicators, and the mechanism of ACEI in therapy with CHF. This paper is aim to study whether the early revascularization could affect the levels of BNP, and the prognostic value of BNP after early revascularization with AMI.Methods1. Seventy adult male were used in the study. Congective heart failure was produced by ligation of the left anterior descending coronary artery in the rats.24hours after myocardial infarction,rats were randomized to untreated infracted group(CHF) or ACEI group (Cilazapril1mg·kg-1·d-1).Sham-operated rats served as control group.After two weeks,these rats were sacrificed.The weight of rats body and heart were measured.The activities of plasma AngⅡ、ET-1were examined by the method of radioimmunoassay test.The gene expression of cardiac TNF-a mRNA and BNP mRNA were measured by reverse transcription-polymerase chain reaction method. We used ELISA to detecet the level of TNF-α、BNP and IL-1β.in circulation.2. Select114patients with AMI for the first time that were admitted. The levels of plasma BNP were measured at admission、at1and7days after admission, according to the status of infarct related artery within6hours whom were devided into patency group and occluded group.And echocardiography was performed within7days after admission in all patient. All patients had been followed-up for24monthes, recorded clinical terminal events.Results1.There was no significant difference in the body weight among the three groups. Heart weight, and heart weight index in the CHF group were significantly increased, and reduced by Cilazapril,but not to the extent of normal.BNP、ET-1、TNF-α were significantly increased in CHF group. But they were reduced in ACEI groups compared with CHF group. CHF enhanced TNF-a mRNAand BNP mRNA expression compared with control group. Treatment with Cilazapril, prevented the CHF-induced rise in the gene expression of TNF-a mRNA and BNP mRNA,but not to the level of normal.2.The levels of BNP at admission were no difference in the two groups, but at1and7days the levels of occluded group were significantly higher(P<0.01).The levels of BNP in three points had positive correlation with LVEDVI、CK、CK-MB、cTnI,but had negative correlaton with LVEF(P<0.05).BNP、Killip classification and the status of infarct related artery within6hours were the independent risk factors for predicting the infaust of cardial events,but by multiple factors cox regression analysis.that levels of BNP2may prognose the infaust of cardial events in2years after AMI.The cut-off point value of BNP determined according to ROC curve was332ng/l and the sensitivity was76.9%, specificity was73.3%.Conclusion:CHF rat after AMI the body weight and heart weight index were significantly higher(P<0.05).The level of plasma BNP、ET-1、TNF-α increased in CHF rats, but reduced by ACEI treatment.The expression of BNP mRNA and TNF-a mRNA in unmyocardial tissue were reduced by ACEI.The level of BNP was an independent risk factor in the infaust prognosis of acute myocardial infarction. Moreover the importance of early revascularization could also be supported with BNP kinetics in maintaining left ventricular function and improving prognosis.