The effects of ejection fraction on N-terminal ProBNP and BNP levels in patients with acute CHF: analysis from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study.

BACKGROUND: Limited data exist regarding the impact of left ventricular ejection fraction (LVEF) on N-terminal pro-brain natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) levels in patients with acute congestive heart failure (CHF). METHODS AND
RESULTS: LVEF data were analyzed for 153 subjects with acute CHF. LVEF > or =50% was defined as non-systolic CHF (NS-CHF); LVEF >50% was defined as systolic CHF (S-CHF). 76 subjects (49.7%) had NS-CHF. Median NT-proBNP and BNP levels were significantly higher among patients with S-CHF (6196 pg/mL, 592 pg/mL, respectively) compared with those patients with NS-CHF (2849 pg/mL, 259 pg/mL, respectively). With optimal cut-points, a false-negative rate of 7% was observed for both assays among patients with S-CHF. Among patients with NS-CHF, BNP had a significantly higher false-negative rate (20%) than did NT-proBNP (9%; P < .001 for difference). NT-proBNP, but not BNP, significantly correlated with CHF symptom severity among patients with NS-CHF.
CONCLUSION: Levels of both NT-proBNP and BNP are significantly lower in patients with NS-CHF; however, in contrast to NT-proBNP, BNP may be falsely negative in up to 20% of patients with NS-CHF and does not correlate with symptom severity in NS-CHF. NT-proBNP appears superior to BNP for the evaluation of suspected acute CHF in patients with preserved LVEF.