The Value Of NT-proBNP For Evaluating The Disease Condition And Prognosis In Patients With Acute ST-segment Elevation Myocardial Infarction

Objective:To investigate the value of NT-proBNP for evaluating the disease condition and prognosis in patients with acute ST-segment elevation myocardial infarction (ST-segment elevation myocardial infarction, STEMI).Methods:1. Two hundred and fourty patients with STEMI were errolled from June2012to June2013, their age of27～96years, mean age of (57.28±15.67) years, among them177males, age of27～96years, mean age of (65.00±33.50) years,63females, age of39～92years, mean age of (72.52±26.50) years, who were admitted in cardiology department of the First Affiliated Hospital of Soochow University. History of hypertension、diabetes、general history、smoking history and alcohol history were recorded. All patients underwent emergency percutaneous coronary intervention(PCI).2. Venous blood of2ml was drewn from all patients within24hours after admission. NT-proBNP concentration was mearsured within two hours. Echocardiography was performed in all patients to measure the left atrial diameter(LAD), left ventricular end-diastolic diameter(LVEDD), left ventricular end-systolic diameter(LVESD) and left ventricular ejection traction(LVEF) was calculated. Biochemical index、cardiac troponin I(cTnI) and blood routine test were mearsured the next day after admission. 3. Follow-up:All patients were followed during hospitalization and within six months after discharge to record the major adverse cardiac events including cardiac death, the emergence of new or worsening heart failure, recurrent myocardial infarction or angina and revascularization.Results:1. Plasma NT-proBNP concentration (1872.00±3502.00) pg/ml] in STEMI patients was positively correlated with the age[(57.28±15.67)years] and LVEDD[(51.40±5.89) mm](r=0.39and0.23respectively, P<0.001), negatively correlated with LVEF[(0.47±0.09)](r=-0.34, P<0.001). Plasma NT-proBNP concentration in STEMI patients increased as Killip grades increased. There were statistical significances between different Killip classes [Killip Ⅰ,Ⅱ,Ⅲ and IV level of NT-proBNP were (940.20±1210.40) pg/ml,(1532.50±1458.10)pg/ml,(3808.50±3855.00)pg/ml and (8491.00±10421.50) pg/ml](P<0.001).2. Plasma NT-proBNP concentration in STEMI patients increased with the number of diseased vessels. The plasma NT-proBNP concentrations of two-vessel disease group [(2390.00±3047.70)pg/ml] and three-vessel disease group[(3478.00±4910.00)pg/ml)] significantly increased compared with single-vessel disease group[(1007.00±1324.50) pg/ml)](P<0.001). The plasma NT-proBNP concentration in STEMI patients with anterior myocardial infarction was the highest.The NT-proBNP concentration of anterior myocardial infarction group [(2647.50±4617.00)pg/ml] was significantly higher than that of inferior wall myocardial infarction group[(1048.50±1806.70)pg/ml] and lateral wall myocardial infarction group[(1007.00±5391.05)pg/ml](P<0.001). There was no significant difference between inferior wall myocardial infarction group and lateral wall myocardial infarction group(P>0.001). The plasma NT-proBNP concentration in STEMI patients also increased with Gensini score. There were significant differences between sifferent Gensini score groups [the plasma NT-proBNP concentrations were (581.15±672.68)pg/ml,(1903.00±1984.25)pg/ml and (5758.00±9685.75)pg/ml from mild, moderate to severe score group(P <0.001)]. There was significant difference of the plasma NT-proBNP concentration between arrhythmia group and non-arrhythmia group[The plasma NT-proBNP concentration in arrhythmia group and non-arrhythmia group were (5596.50±8067.00)pg/ml and (984.40±990.20)pg/ml](P<0.001).3. Nine patiernts died during follow-up. The Plasma NT-proBNP concentration of MACE group was signifficantly higher than that of non-MACE group[(5936.00±9396.00)pg/ml VS (1067.00±1182.50)pg/ml](P <0.001). Logistic regression analysis showed that the MACE was related with the age, Log (NT-proBNP), cTnI and hs-CRP, whereas Log (NT-proBNP) was the strongest predictor of MACE(P<0.001). Receiver operating characteristic(ROC) curve analysis showed that the best cut-off value of NT-proBNP was4069.50pg/ml for predicting MACE(sensitivity0.71,1specificity=0.05, Youden index=0.66).Conclusions:1. The plasma NT-proBNP concentration in STEMI patients is correlated with the severity of disease condition with positive correlation with age and LVEDD and negative correlation with LVEF. The plasma NT-proBNP concentration in STEMI patients increases as Killip grade increases.2. The plasma NT-proBNP concentration in STEMI patients with anterior myocardial infarction is the highest. The plasma NT-proBNP concentration in STEMI patients increases with Gensini score increases. The plasma NT-proBNP concentration significantly increases in arrhythmia group and MACE group.3. The plasma NT-proBNP concentration in STEMI patients is the strongest predictor of MACE. ROC curve analysis shows that the best cut-off value of NT-proBNP concentration is4069.50pg/ml for evaluating the occurrence of MACE.