HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Jaffe, A. S. Articles by Babuin, L. Search for Related Content PubMed PubMed Citation Articles by Jaffe, A. S. Articles by Babuin, L. Related Collections Heart Health and the Clinical Laboratory Proteomics and Protein Markers

Why We Don’t Know the Answer May Be More Important than the Specific Question

¹ Mayo Clinic, Rochester, MN
² Hennepin County Medical Center, Minneapolis, MN

^aAuthor for correspondence.

The first 300 words of the full text of this article appear below.

Kemperman et al. (1) have evaluated the relationship of B-type natriuretic peptide (BNP; measured by the Bayer assay) and N-terminal proBNP (NT-proBNP; measured by the Roche assay) in patients treated with a left ventricular assist device (LVAD). They report that the relationship of the results of the two assays changes after prolonged support on a LVAD. Before LVAD use, the ratio of NT-proBNP to BNP is higher than after improvements in hemodynamics with use of the LVAD. They suggest that the initial high ratio reflects impaired renal clearance of NT-proBNP because of abnormal hemodynamics and that the subsequent decrease in the ratio reflects improved renal clearance in response to LVAD support. This may be the case and is one reasonable interpretation of the data given that glomerular filtration was significantly, although modestly, reduced in most patients before use of the LVAD. This hypothesis is consistent with other data suggesting a relationship between BNP and NT-proBNP and renal function (2). However, other explanations are possible, relating to the characteristics of the assays themselves and to physiologic factors in this special group of patients. Many of the issues we will raise ideally should have been explored during the development of the natriuretic assays themselves or during their clinical validation. Thus, there is a need not only to reflect on the specific issues related to BNP and NT-proBNP in patients with impaired renal function but also to ask why, so often, the critical analytical and clinical data that would help answer questions like this are not available in the literature.

Initial analytical validation studies tend to be designed to allow an assay to be shown to be useful and/or to pass regulatory muster. There is then some attempt to define a normal reference interval and ultimately an attempt to . . . [Full Text of this Article]

Note added in proof:

The following articles in journals at HighWire Press have cited this article:

				B. Vaes, W. de Ruijter, J. Gussekloo, and J. Degryse The accuracy of plasma natriuretic peptide levels for diagnosis of cardiac dysfunction and chronic heart failure in community-dwelling elderly: a systematic review Age Ageing, November 1, 2009; 38(6): 655 - 662. [Abstract] [Full Text] [PDF]

				R. R.J. van Kimmenade, J. L. Januzzi Jr, J. A. Bakker, A. J. Houben, R. Rennenberg, A. A. Kroon, H. J.G.M. Crijns, M. P. van Dieijen-Visser, P. W. de Leeuw, and Y. M. Pinto Renal clearance of B-type natriuretic peptide and amino terminal pro-B-type natriuretic peptide a mechanistic study in hypertensive subjects. J. Am. Coll. Cardiol., March 10, 2009; 53(10): 884 - 890. [Abstract] [Full Text] [PDF]

				I. Giuliani, F. Rieunier, C. Larue, J.-F. Delagneau, C. Granier, B. Pau, M. Ferriere, M. Saussine, J.-P. Cristol, A.-M. Dupuy, et al. Assay for Measurement of Intact B-Type Natriuretic Peptide Prohormone in Blood Clin. Chem., June 1, 2006; 52(6): 1054 - 1061. [Abstract] [Full Text] [PDF]