N-terminal pro-brain natriuretic peptide for discriminating between cardiac and non-cardiac dyspnoea

Evaluation of N-terminal pro-brain natriuretic peptide (NT-proBNP) to confirm or disprove heart failure in community patients complaining of dyspnoea.

General practitioners referred 345 consecutive patients complaining of dyspnoea to our hospital-based clinic, where a diagnosis was established based on a combined programme for heart and lung diseases including echocardiography. The level of NT-proBNP in plasma was also measured. The mean (S.D.) concentration of NT-proBNP in patients with heart failure was significantly higher, 189 (270) pmol/l in patients with heart failure (n=81), than in patients with non-cardiac dyspnoea (n=264), 17 (38) pmol/l (P<0.001). In patients > or = 50 years NT-proBNP <11 pmol/l for men and <17 pmol/l for women excluded heart failure with a negative predictive value of 97% while the positive predictive value was 53%, the sensitivity 95% and the specificity 68%. Areas under receiver operator characteristic curves for men and women were 0.93 and 0.90, respectively.

In a relevant setting of primary care patients complaining of dyspnoea, NT-proBNP seems promising for disproval of heart failure, and this test may reduce the need for echocardiographic screening with 50%. However, the discrimination levels of NT-proBNP found in this study may need prospective confirmation, before the test can be generally recommended.