Anemia considerations when assessing natriuretic peptide levels in ED patients

The incidence of heart failure (HF) has reached epidemic levels in western populations, and the majority of these patients are admitted to hospitals through the emergency department (ED). We aimed to aid clinicians assessing natriuretic peptide (NP) levels in cases with suspected HF. In this study, we investigated the effect of anemia on amino-terminal pro-BNP (NT-proBNP) and on B-type natriuretic peptide (BNP) levels.

This retrospective study examined patients who were admitted to the ED with suspected HF. After admission, the treating physician requested complete blood count and creatinine tests with NT-proBNP (n=2.637) or BNP (n=11.159). The exclusion criteria were used to minimize the factors that could affect the NT-proBNP and BNP results. We examined the data using the Mann-Whitney U test, Chi-square test, Spearman correlation test, and multivariate linear regression analyses.

The NT-proBNP and BNP levels were statistically higher in the groups with anemia (p=0.016 and p=0.009, respectively). There was a statistically significant negative correlation between hemoglobin and NP levels (r=-0.272, p<0.001 for NT-proBNP and r=-0.179, p<0.001 for BNP). The results indicated that advanced age and low hemoglobin levels were significantly associated with the increase in NT-proBNP (p=0.024 and p=0.004, respectively). Advanced age, low hemoglobin and low GFR-MDRD levels were significantly associated with the increase in BNP (p<0.001, p=0.002 and p=0.013, respectively).

The data suggest that clinicians examining patients admitted to the ED with suspected HF should consider that anemia could lead to increases in NT-proBNP and BNP levels.