Prognostic Implications of Serum B-type Natriuretic Peptide in Heart Failure

Cho, Hyoung Min; Sohn, Seok Joon; Kim, Seoung Gu

Abstract

Serum level of B-type natriuretic peptide (BNP) has been reported to be useful in diagnosing the cause of dyspnea at emergency room. However, it remains controversial whether serum BNP determined at emergency room can also be useful in predicting the prognosis of resting dyspneic patients. Therefore, we attempted to clarify the predictability of serum BNP in heart failure patient with dyspnea in resting state (NYHA class IV). Fifty one patients (M, 25; F, 26) who had been complaining of resting dyspnea were analyzed. two-dimensional echocardiography was done and serum B-type natriuretic peptide was checked at emergency room. The prognosis was classified into three groups: mortality, morbidity and good prognosis. "Mortality" included the cases expired during admission or within three months (Group 1), "morbidity" was defined as cases admitted longer than 14 days or readmitted within three months (Group 2), and "good prognosis" group was defined as those discharged within 14 days after management (Group 3). Serum BNP of three groups was determined as 3,292+/-1,321 pg/ml, 1,648+/-1,044 pg/ml and 1,210+/-937 pg/ml, respectively. Logistic regression was done. The serum BNP level was significantly higher in group 1, compared with other groups (p <0.001). On the contrary, the ejection fraction (EF) in two-dimensional echocardiography was not different among three groups, indicating that EF has no predictory value for the prognosis of severe dyspneic heart failure cases. The ROC plot analysis indicates, the mortality rate substantially increased if serum BNP value is higher than 2,000 pg/ml (AUC=0.881, p <0.001). It is concluded that the serum BNP can be useful also in predicting the prognosis as well as in diagnosing the heart failure, and that it can serve as a more accurate predictor of prognosis in cases with severe heart failure.