Correlation between B-type natriuretic peptide and N-terminal pro-brain natriuretic peptide in patients presenting to an emergency department with decompensated heart failure

Background

B-type natriuretic peptide (BNP) and N-terminal probrain natriuretic peptide (NT-proBNP) have been used to assess patients with heart failure. Few studies have compared both markers in patients who present to the emergency department (ED) with decompensated heart failure (HF).

Methods

We studied 40 patients who presented to an ED with decompensated HF diagnosed by means of clinical judgement (Framingham criteria). The mean age was 80.3 ± 10.4 years, and 18 (45%) were male. Thirty-four (85%) patients were NYHA class III or IV. Ischemic HF was present in 25 (62.5%) patients. The mean ejection fraction was 46 ± 19.2%. Both BNP and NT-proBNP were measured at the moment of admission to the ED. The correlation between the two markers was assessed by the Pearson coefficient test.

Results

Mean values for BNP and NT-proBNP were 943.2 ± 821.2 and 10,436.7 ± 14,721 pg/ml, respectively. A strong correlation was observed between the two markers (r = 0.81, P < 0.001). NT-proBNP values were much higher than BNP values in all patients but one, whose values were 165 pg/ml and 1620 pg/ml.

Conclusion

A good correlation was observed between BNP and NT-proBNP. The ratio between NT-proBNP and BNP was much higher than usually reported in outpatient settings. This could reflect a proportionally greater reduction in renal elimination of NT-proBNP in this population with severe decompensated HF.