Risk of cardiovascular death in elderly patients with possible heart failure. B-type natriuretic peptide (BNP) and the aminoterminal fragment of ProBNP (N-terminal proBNP) as prognostic indicators in a 6-year follow-up of a primary care population

Abstract

Heart failure is common in the elderly population and carries a serious prognosis. We evaluated EDTA-plasma B-type natriuretic peptide (brain natriuretic peptide, BNP) and the aminoterminal fragment of proBNP (N-terminal proBNP) as prognostic markers in elderly primary care patients with symptoms of heart failure.

Methods: From 474 patients attending primary care for symptoms of dyspnea, fatigue and/or peripheral edema, blood was sampled in plastic tubes containing EDTA to measure BNP by non-extraction immunoradiometric assay and N-terminal proBNP by non-extraction radioimmunoassay. Patients were evaluated with respect to history and function by NYHA classification and Doppler echocardiography. Follow-up time was 6 years. Cox regression analysis was performed to identify the weight of risk variables.

Conclusion: Total 6-year mortality was 20% (102 patients out of 510), and cardiovascular (CV) mortality was 14% (71 patients, 70% of total mortality). BNP and N-terminal proBNP were essentially equally useful as prognostic markers. In patients with the highest quartiles of plasma concentration of BNP and N-terminal proBNP, respectively, the risk of cardiovascular mortality was 10 and 4.8 times, respectively, higher than that in those in the lowest quartile. Peptide concentrations varied widely within all functional groups including those with normal echocardiographic findings. Plasma concentrations of BNP and N-terminal proBNP give important prognostic information concerning risk of cardiovascular mortality. Cost-effective "clinical pathways" should be outlined for patients with elevated peptide concentrations.