Natriuretic peptide B plasma concentration increases in the first 12 h of pulmonary edema recovery.

Background: According to guidelines, single determination of B-type Natriuretic peptide (BNP) should be used for distinguishing between cardiac and non-cardiac acute dyspnea at the emergency room. BNP measurement is also recommended before hospital discharge in patients hospitalized for heart failure to assess prognosis and to evaluate treatment efficacy. In acute cardiogenic pulmonary edema, BNP is measured using a single BNP determination, but the temporal behavior of BNP during pulmonary edema recovery is unknown.

Methods: Fifty chronic low ejection fraction (<40%) heart failure patients (age 77 ± 9 years, 17 M-33F) admitted for acute pulmonary edema were studied. Patients were grouped according to 50% dyspnea recovery time into 3 groups: ≤30 min (n = 14), 30 to 60 min (n = 19), and > 60 min (n = 17). BNP was measured at arrival and 4, 8, 12 and 24 h afterwards.

Results: At arrival, BNP was elevated in all patients without significant difference among groups. In the entire population, BNP median and interquartile range value were 791 (528-1327) pg/ml, 785(559-1299) pg/ml, 1014(761-1573) pg/ml, 1049(784-1412) pg/ml, 805(497-1271) pg/ml at arrival and 4, 8, 12 and 24 h afterwards, respectively, showing higher values at 8 and 12 h. This peculiar temporal behavior of BNP was shared by all study groups. Patients with the longest edema resolution showed the highest BNP level 8 and 12 h after admission.

Conclusions: In acute pulmonary edema, BNP increased up to 12 h after emergency admission regardless of dyspnea recovery time, making BNP quantitative meaning in the acute phase of pulmonary edema uncertain.