The Clinical Value of TnI and BNP for the Evaluation of Sepsis-related Cardiac Dysfunction in the Emergency Department

ABSTRACT

PURPOSE: Acute cardiac dysfunction is a well recognized manifestation of organ failure in severe sepsis and septic shock. Although echocardiography is the golden standard for the evaluation of cardiac dysfunction, it is difficult to use in the emergency department (ED). The purpose of this study was to determine the availability of cardiac biomarkers for the estimation of cardiac dysfunction in septic shock patients. METHODS: All study subjects included consecutive patients with septic shock diagnosed in the ED and treated with an algorithm of early goal-directed therapy between January 2011 and June 2012. We enrolled patients measured for cardiac biomarkers and performed echocardiography within 24 hours. We divided patients into two groups based on the occurrence of left ventricular dysfunction (defined as an ejection fraction< or =40%) and compared serum levels of troponin-I (TnI) and B-type natriuretic peptide (BNP) between the two groups. The area under the receiver operating characteristic (ROC) curve was used to compare the diagnostic ability of TnI and BNP. RESULTS: A total of 127 patients with septic shock and evaluated for cardiac dysfunction were enrolled in this study. TnI and BNP were significantly higher in the left ventricular dysfunction group group (4.2+/-9.0 vs. 0.6+/-1.8 ng/mL, respectively, p<0.05) compared with the non-dysfunction group (1087.6+/-680.1 vs. 633.2+/-859.1 pg/mL, respectively, p<0.05). However, in the ROC curve for predicting left ventricular dysfunction, the area under the curves of TnI and BNP, respectively, were 0.631(95% CI 0.473-0.788, p=0.103) and 0.704 (95% CI 0.552-0.856, p=0.011). TnI and BNP showed a 84.6% negative predictive value. CONCLUSION: Although TnI and BNP were significantly higher in septic shock patients with cardiac dysfunction but demonstrated limited accuracy compared to echocardiography. However, TnI and BNP have high negative predictive value in septic shock patients for the evaluation of cardiac dysfunction. Therefore they could serve as a valuable supplement for the detection of cardiac dysfunction.