Aims: To compare the ability of different B-type natriuretic peptide (BNP) assays to identify heart failure in stable elderly patients with a diagnosis of chronic obstructive pulmonary disease (COPD).
Methods: 200 patients aged >or=65 years with COPD according to their general practitioner and without known heart failure, underwent a diagnostic work-up. The final diagnosis of heart failure was established by a panel using the diagnostic principles of the European Society of Cardiology. All available diagnostic results, including echocardiography, but not BNP or NT-proBNP measurements, were used. The ability of different B-type natriuretic peptide assays to identify heart failure was estimated using the area under the receiver operating characteristic curves (ROC-area).
Results: The ROC-areas did not differ significantly between the various assays of NT-proBNP and BNP, and ranged from 0.68 (95%CI 0.60-0.73) to 0.73 (95%CI 0.64-0.81). For NT-proBNP the age- and gender-independent 'optimal' cut-point was 15 pmol/l (125 pg/ml) and for BNP 10 pmol/l (35 pg/ml). All assays were much better at excluding than detecting heart failure.
Conclusions: All assays of B-type natriuretic peptide showed reasonable and comparable accuracy in recognising heart failure. At 'optimal' cut-points, all assays performed better at excluding than detecting new cases of heart failure in this population.