The Optimal Threshold for Detection of BNP in Congestive Heart Failure and Variables Impact on BNP Concentration

ABSTRACT

PURPOSE: This study was conducted in order to determine a cut-off value of BNP for use in our hospital, and to obtain mean values of BNP as correlated to various factors and to underlying disease. After classification of patients into groups according to disease severity and prognosis, we analyzed the correlation between the concentration of mean BNP and severity of disease. METHODS: 1040 patients who visited the emergency department of the hospital between July 1, 2004 and July 31, 2005 and whose BNP values were measured were enrolled in the study. RESULTS: The optimal threshold BNP concentration for detection of heart failure was 296 pg/mL. The mean BNP concentration in female patients without underlying disease and heart failure was increased significantly and in patients with CRF, the cut-off value of BNP for a CHF was 413 pg/ml. In patients with more than two types of underlying disease, significant increase in mean BNP concentration was found in patients with hypertension. As indicated by New York Heart Association Killip classification, the left ventricular ejection fraction and prognosis, the BNP value is correlates both with the severity of heart failure and with its prognoses. CONCLUSION: The BNP concentration used as a clinical indicator in our hospital is much higher than the cut-off value of 100pg/mL. In patients without CHF, women are higher in mean BNP concentration. A significantly higher mean BNP concentration was found in patients with hypertension. We find that BNP concentration is related both to the severity of heart failure and to prognoses.