Neither Race nor Gender Influences the Usefulness of Amino-Terminal Pro-Brain Natriuretic Peptide Testing in Dyspneic Subjects: A ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) Substudy

Abstract

Background Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful for the diagnosis and exclusion of congestive heart failure (HF). Little is known about the effect of race on NT-proBNP concentrations. Also, NT-proBNP levels may be higher in apparently well women, but the effect of gender on NT-proBNP concentrations in dyspneic patients is not known. Methods and Results NT-proBNP (Elecsys proBNP, Roche, Indianapolis, IN) was measured in 599 dyspneic patients in a prospective study. Of these, 44 were African American; 295 were female. NT-proBNP levels were examined according to race and gender in patients with and without acute HF using analysis of covariance. Receiver operating characteristic (ROC) curves assessed NT-proBNP by race and gender. Cutpoints for diagnosis (450, 900, and 1800 pg/mL for ages <50, 50 to 75, and >75 years) and exclusion (300 pg/mL) were examined in African-American and female subjects. There was no difference in the rates of acute HF between African-American and non–African-American (30% versus 35%, P = .44) or male and female (35% versus 35%, P = .86) subjects. In subjects with HF, there was no difference in median NT-proBNP concentrations between African American and non–African American (6196 versus 3597 pg/mL, P = .37). In subjects without HF, unadjusted NT-proBNP levels were lower in African-American subjects than in non–African-American subjects (68 versus 148 pg/mL, P < .03); however, when adjusted for factors known to influence NT-proBNP concentrations (age, prior HF, creatinine clearance, atrial fibrillation, and body mass index), race no longer significantly affected NT-proBNP concentrations. There was no statistical difference in median NT-proBNP concentrations between male and female subjects with (4686 versus 3622 pg/mL, P = .53) or without HF (116 pg/mL versus 150 pg/mL, P = .62). Among African Americans, NT-proBNP had an area under the ROC for acute HF of 0.96 ( P < .0001), and at optimal cutpoints, had a sensitivity of 100% and a specificity of 90%. Among females, NT-proBNP had an area under the ROC for acute HF of 0.95 ( P < .0001), and had a sensitivity of 89% and a specificity of 88%; 300 pg/mL had negative predictive value of 100% in African Americans and females. Conclusion NT-proBNP is useful for the diagnosis and exclusion of acute HF in dyspneic subjects, irrespective of race or gender.