Objective To investigate the serum concentration of N-amino terminal pro-brain natriuretic peptide (NT-proBNP) in elderly patients (aged 70 years and older) based on the chronic heart failure (CHF) stages,NYHA function classification,and left ventricular ejection fraction (LVEF).Methods CHF stages and NYHA function classification were determined for 121 patients on admission.LVEF and LVEDD were assessed by echocardiography and NT-proBNP was assayed by Roche Diagnostics.Results (1) The median NT-proBNP level...