Diagnostic performance and cost effectiveness of measurements of plasma N-terminal pro brain natriuretic peptide in patients presenting with acute dyspnea or peripheral edema☆

Abstract 

Background

The purpose of this study was to determine the diagnostic power of a newly available assay for amino-terminal pro-brain natriuretic peptide (NT-proBNP) to identify patients with acute heart failure. In addition, the influence of initial NT-proBNP measurements on economic consequences, diagnostic procedures and staff involvement was evaluated.

Methods and results

401 patients presenting with acute dyspnea or peripheral edema in the emergency department were enrolled. NT-proBNP was measured after initial clinical evaluation. Clinical routine care and diagnostic assessment were blinded to NT-proBNP results. Two cardiologists independently validated the period of hospitalization, clinical examinations and medical therapies of each patient considering NT-proBNP results. The median NT-proBNP level among patients with acute congestive heart failure (CHF) (n=122) was 3497 pg/ml as compared to 320 pg/ml in patients without (n=279) (p<0.0001). An NT-proBNP cutoff level <300 pg/ml was optimal to rule out acute CHF (negative predictive value 96%; sensitivity 96%). NT-proBNP ≥300 pg/ml could strongly predict acute CHF when compared to patients' history or physical examination (odds ratio 9.5; p<0.0001) and diagnostic technical findings (odds ratio 14.7; p<0.05). In patients with NT-proBNP<300 pg/ml, 14% of the period of hospitalization could be saved, corresponding to savings of US $481 per patient. In addition, 9% of the number and time of staff involvement of clinical examinations and therapies could be saved, 10% of the costs of clinical examinations. Chest X-rays were saved in 34%, echocardiography in 9%.

Conclusions

Measurement of NT-proBNP leads to multiple saving amounts and optimizes diagnostic pathways and resource allocation.

Keywords: Cost, Dyspnea, Edema, Heart failure, NT-proBNP