Differentiating acute heart failure from pulmonary disease is important for patients admitting to emergency department because of dyspnea. NT-proBNP is recently obtained a fast, accurate test to diagnosis acute heart failure in patients presenting with dyspnea. Methods: This is a prospective study. 80 patients presenting with acute dyspnea in the Emergency department, Thanh Nhan hospital were end rolled. NT-proBNP were taken at the first time when the patients admitted. Results: The area under the receiver operating curve was 0,94 and with the cutpoint 899 pg/ml NT-proBNP was highly sensitive and specific for diagnosis acute heart failure: Patients with heart failure had the median NT-proBNP level higher the other (3455 +/- 1642 vs 256 +/- 231
p0,001). The concentrate of NT-proBNP in the blood 800 pg/ml helped to except 98 percent for diagnosis acute heart failure. NT-proBNP was superior to clinical judgement for diagnosis acute heart failure. Conclusions: With the cut-off point 800pg/ml, NT-proBNP is a valuable test for diagnosis acute heart failure in Emergency department.