Amino-terminal pro-brain natriuretic peptid in prediction of left ventricular ejection fraction

We aimed to evaluate levels of amino-terminal pro-brain natriuretic peptide (NT-proBNP) in prediction of left ventricular ejection fraction (LVEF) in heart failure patients. Prospective study on 60 consecutive patients with symptoms and signs of heart failure was perfomed. Blood samples for NT-proBNP analysis was taken from all test subjects and echocardiography was also done in all of them. According to LVEf value, patients were divided into four groups; those with <= 30%, 31 to 39% 40 to 49% and >= 50%. NT-proBNP values correlated with LVEF value. Regression analysis was used to evaluate how well NT-proBNP values predict LVEF. We used Receiver Operating Characteristic Curve calculation to evaluate diagnosis performance of NT-proBNP in estimation of LVEF. Average value of NT-proBNP in test group was 3191, 69 +/- 642,89 pg/ml (p < 0,001). Average value of NT-proBNP decreased with higher LVEF categories with significatn (p < 0.001) and high negative correlation (r = -0,75). Stepwise multivariate linear regression analysis showed that logarithmic value of NT-proBNP was excellent predictor of LVEF value (p < 0,05). Model equation based on regression analysis was LVEF = 88,645-15,311 x log (NT-proBNP). Predictive model for LVEF yielded from regression analysis had sensitivities of 98% and 81% specificities of 20% and 90% positive predictive values of 86% and 78% and negative predictive values pf 67% and 92% for predicting patients with LVEF < 50% and LVEF < 40% respectively. There was negative linear correlation between NT-proBNP and LVEF. NT-proBNP was excellent predictor of LVEF value (p < 0,05).