Comparison of brain natriuretic peptide and probrain natriuretic peptide in the diagnosis of cardiogenic pulmonary edema in patients aged 65 and older.J Am Geriatr Soc. 2005 Apr; 53(4):643-8.JA
Differentiating cardiogenic pulmonary edema (CPE) from respiratory causes of dyspnea is difficult in elderly patients. The aim of this study was to compare the usefulness of B-type natriuretic peptide (BNP) and amino-terminal fragment BNP (proBNP), to diagnose CPE in patients aged 65 and older.
Medical emergency department of a 2,000-bed urban teaching hospital.
Patients aged 65 and older presenting with acute dyspnea and a respiratory rate of 25 breaths/min or greater, a partial pressure of oxygen of 70 mmHg or less, or an oxygen saturation of 92% or less were included.
Rapid BNP and proBNP assays, performed blind at admission, were compared with the final diagnosis (CPE or no CPE) as defined by an expert team.
Two hundred two patients (mean age+/-standard deviation 80+/-9) were included; 88 (44%) had CPE. There was a strong correlation between proBNP and BNP values (correlation coefficient=0.91, P<.001). The median BNP and proBNP were higher in the group of patients with CPE (377 vs 74 pg/mL, P<.001, and 3,851 vs 495 pg/mL, P<.001, respectively). The best threshold values of BNP and proBNP were 250 pg/mL and 1,500 pg/mL, respectively. The area under the receiver operating characteristic curve was greater with BNP than with proBNP (0.85 vs 0.80, P<.05). BNP assay was more accurate in diagnosis than the emergency physician, whereas proBNP was not. Higher values of BNP and proBNP were associated with greater in-hospital mortality.
BNP assay is a more useful diagnostic indicator for CPE than proBNP in patients aged 65 and older.