| Background and Purpose Heart failure,as a pathophysical process,includes left ventricular systolic dysfunction (LVSD) and left ventricular diastolic dysfunction(LVDD).All of them will induce left ventricular end-diastolic pressure to increase,vein congestion and bring to symptoms of congestive heart failure(CHF). Brain natriuretic peptide(BNP) is a cardiac hormone secreted from the ventricles in response to ventricular volume expansion or pressure overload.So BNP reflects left ventricular dysfunction(LVD).European Society of Cardiology (ESC) and American College of Cardiology(ACC) regard BNP as assistant diagnostic standard of heart failure.BNP is also widely used to predict morbidity and mortality of CHF patients and BNP level would decrease significantly after effective treatment in CHF patients. Myocardial ischemia will induce LVDD because calcium balance was broken as result of disturbance of myocardial energy metabolism.Trimetazidine(TMZ),which stimulate glucose oxidation by inhibiting fat acid oxidation ,produce more ATP by consuming limited oxygen.TMZ,which could reduce intracellular acidosis and calcium overload,could also improve left ventricular diastolic function significantly.The effect of metoprolol in CHF patients was proved by MERIT-HF.CHIME study also evaluates effect and safety of metoprolol in CHF patients. The experiment,which will observe plasma BNP level of LVDD in coronary artery disease(CAD) patients and LVSD patients in CHIME study,respectively on medication of TMZ and metoprolol,compared with control group,will investigate changes of BNP after treatment in LVD patients. METHODS LVDD patients in CAD who had been hospitalized were randomly divided into control group and treatment group,and were given general remedy or TMZ for 4 weeks respectively.After treatment,we observe the changes of BNP between groups.Furthermore we collectted patients from control group and high dose metoprolol group(metoprolol≥100mg/d) in CHIME study to observe plasma BNP difference between groups after long term treatment and to investigate correlation between BNP and ultrasound values. RESULTS All LVDD patients in CAD were 43,21 patients in control group and 22 patients in treatment group.BNP level had no statistic difference between two groups before treatment.After 4 weeks,BNP level increased in control group and decreased in treatment group,and BNP level had significant difference between groups(P=0.042). By receiver operating characteristic (ROC) curve,BNP cutoff value of 12.75pg/ml had a sensitivity of 95.3%,a specificity of 80%,an accuracy of 87.8% for diagnosis in LVDD. Patients collected from CHIME study were 37,including 15 patients in control group and 22 patients in metoprolol group.In metoprolol group,LVEF increased and LVEDD,LVESD,LAD,HR,DBP decreased significantly after treatment(P was <0.001,0.007,0.04,0.005,0.001,0.009 respectively),SBP had no significant change;in control group,each variable had no statistic difference after treatment(P>0.05).All cardiac parameters in metoprolol group indicated more evident improvement than those in control group although all data after treatment had no statisticdifference between groups.BNP in metoprolol group was higher than that in control group,but had no statistic significance. Combined data in two parts,we could find that BNP,LVEDD,LAD,C/T in LVSD patients were more than those in non-LVSD patients significantly(P was 0.01,<0.001,0.008,0.04).BNP level significantly correlated with LVEF and LVEDD(r was –0.481,0.311;P was <0.001,0.005).By ROC curve,BNP cutoff value of 58.75pg/ml had a sensitivity of 65.2%,a specificity of 78.9%,an accuracy of 74.8% for diagnosis in LVSD. CONCLUSION TMZ had a positive effect on LVDD of CAD patients and plasma BNP level had better sensitivity than echocardiography for follow-up visit in LVDD;BNP level had negative correlation with LVEF and positive correlation with LVEDD.However,plasma BNP level was not a good indicator on medication of β-blocker in CHF patients. |
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