[The predictive value of B-type natriuretic peptide for the mortality from acute myocardial infarction].

ABSTRACT

OBJECTIVE: To explore the predictive value of B-type natriuretic peptide (BNP) for the mortality of acute myocardial infarction (AMI). METHODS: Follow-up was made in 264 consecutive patients with AMI, with an average period of (14.7 +/- 5.3) months and follow-up rate of 87.1% (230 cases). Cardiac death was recorded in the 1st, 6th and 12th month after AMI. Among one to seven days after AMI, the MB isoenzyme of creatine kinase (CK-MB), troponin T (TnT), echocardiographically measured left ventricular end-diastolic internal diameter (LVEDd), left ventricular ejection fraction (LVEF) and BNP were determined. The Receiver Operating Characteristic (ROC) were drawn to determine the predictive value for the cardiac death after AMI comparing BNP with the classical risk factors mentioned above. Analysis was made to define the relative independent risk factors of cardiac death and non-cardiac death survival rate after AMI. RESULTS: The ROC curves comparing CK-MB, TnT, LVEDd and LVEF with BNP and lnBNP showed that BNP was the only index for predicting cardiac death after AMI, the cut off point value of BNP determined according to ROC curve was 864 ng/L and the sensitivity, specificity, accuracy, positive and negative predictive values for predicting the cardiac death was 76.2% - 92.9%, 84.3% - 85.6%, 82.2% - 86.1%, 21.3% - 36.2% and 97.3% - 98.9% at the 1st 16th, 12th month after AMI respectively. Furthermore, BNP showed the only independent risk factor for predicting the cardiac death in the short and long term period after AMI (P < 0.01) by multiple factors cox regression analysis. The non-cardiac death survival rate in the group of BNP level < or = 864 ng/L was significantly higher than that in the group of BNP > 864 ng/L (97.3% vs 72.3%, P < 0.001), and the median survival time of the dead in the former group was also significantly longer than in the latter group (16.0 vs 10.7, P < 0.01), no matter whether they were suffering from AMI with ST elevation or not, treated with or without primary PCI. CONCLUSION: BNP has the best predictive value for mortality after AMI compared with other traditional indexes.