Intended for healthcare professionals

Rapid response to:

Papers

How well does B-type natriuretic peptide predict death and cardiac events in patients with heart failure: systematic review

BMJ 2005; 330 doi: https://doi.org/10.1136/bmj.330.7492.625 (Published 17 March 2005) Cite this as: BMJ 2005;330:625

Rapid Response:

Analytical problems with BNP determining

Two serious analytical problems with B-Type Natriuretic Peptide (BNP) determining are discuted in professional literature: First, the high intraindividual biological variation hamper interpretation of changes in BNP concentrations and may partly explain his poor diagnostic value in chronic heart failure. The value of BNP for follow-up and treatment optimization, and for prognosis determining, remains largely to be established (1). Second, diagnostic accuracy, and prognosis determining, too, can strongly depend on patient selection and on the cardiac natriuretic peptide assayed (BNP, N-terminal pro-A-type natruretic peptide, or NT-proBNP), as well as on the analytical performance and diagnostic accuracy of the immunoassay chosen (2). Analytic bias caused by assay differences and reagent variations can cause major problems for clinicians trying to interpret the test results. There's no other alternative, better assy harmonisation could improve practice and simplify the problems of having each local laboratory responsible for establishing their own reference intervals and medical decision limits.

1. Bruins S, Fokkema MR, Romer JWP, DeJongste MJL, van der Dijst FPL, van den Ouweland JMW, Muskiet FAJ. High intraindividual variation of B- type natriuretic peptide (BNP) and Amino-terminal proBNP in patients with stable chronic heart failure. Clin Chem 2004;50:2052-2058. 2. Clerico A, Prontera C, Emdin M, Passino C, Storti S, Poletti R et al. Analytical performance and diagnostic accuracy of immunometric assys for the measurement of plasma B-type natriuretic peptide (BNP) and N-terminal proBNP. Clin Chem 2005;51:445-447.

Competing interests: None declared

Competing interests: No competing interests

19 March 2005
Rudolf Gasko
clinical biochemist
Health Insurance Company, Murgasova 3, SK-043 25 Kosice, Slovakia