Relationship Between N-terminal Pro-B-type Natriuretic Peptide And The Extent Of Myocardial Infarction And Prognosis In Patients With ST-segment Elevation Acute Myocardial Infarction

Objective:To investigate the relationship between N-terminal pro-B-type natriuretic peptide (NT-proBNP) and the extent of infracted myocardium and the prognosis in patients with ST segment elevation acute myocardial infarction (STEAMI).Methods:122patients with ST segment elevation acute myocardial infarction(STEAMI) within12hours, and64controls were included in this study. NT-proBNP concentration was measured as soon as admission by enzyme linked immunosorbent assay. Killip classification, the peak of CK, CK-MB and cTNI was recorded. QRS score was calculated according to ECG after5-7days of AMI. At the same time, UCG was emplied to evaluate LVEF and LVEDD. All patients were followed up for6months. Cardiac death, recurrent myocardial infarction and readmission of heart failure were recorded.Result:1. The level of NT-proBNP in STEAMI patients was higher than controls, lgNT-proBNP was2.31±0.73and1.95±0.47respectively, and the inter-group differences was statistically significant(P<0.01).2. LgNT-proBNP in STEAMI-patients with cardiac insufficiency and without cardiac insufficiency was2.24±0.71vs2.83±0.67, it was statistically higher in patients accompanied by heart insufficiency(P<0.01).3. NT-proBNP concentration was positively correlated with CK-MB concentration (r=0.187, P=0.039), Killip classification (r=0.289, P=0.001), QRS score (r=0.206, P=0.023), and it was negtively correlated with LVEF (r=-0.289, P<0.001)4. NT-proBNP level was independently correlated with QRS score by multiple stepwise regression analysis (r=0.001> P=0.01)5. Logistic regression analysis demonstrated that NT-proBNP>145.0ng/ml was independently correlated recurrent myocardial infarction (OR=2.541,95%CI:1.160～5.900. P=0.023) and heart failure (OR=2.062,95%CI:1.511-6.055, P= 0.039) during six-month follow-up.6. To detect recurrent myocardial infarction after6months, the area under the ROC curve was0.753(95%CI:0.608～0.898, P=0.008). To detect heart failure after6months, the area under the ROC curve was0.788(95%CI:0.679-0.898, P=0.003). From the ROC, the coordinate of sensitivity90%and specificity66.1%was considered as the cutoff point, and relatively,228.2ng/ml to be the optimum diagnostic threshold.Conclusion:The plasma NT-proBNP level was correlated with the size of myocardial infarcion and the short-term prognosis in STEAMI patients.