European Heart Journal Advance Access originally published online on January 11, 2007
European Heart Journal 2007 28(2):177-182; doi:10.1093/eurheartj/ehl449
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Long-term clinical variation of NT-proBNP in stable chronic heart failure patients
1 Department of Cardiology and Endocrinology, Clinic E, Frederiksberg University Hospital, Ndr. Fasanvej 57–59, DK-2000 Frederiksberg, Denmark
2 Department of Cardiology, The Heart Centre, Rigshospitalet University Hospital, DK-2100 Copenhagen, Denmark
3 Department of Clinical Physiology and Nuclear Medicine and PET, Rigshospitalet University Hospital, DK-2100 Copenhagen, Denmark
4 Cluster for Molecular Imaging, Department of Medical Physiology, University of Copenhagen, DK-2200 Copenhagen, Denmark
Received 31 March 2006; revised 21 November 2006; accepted 30 November 2006; online publish-ahead-of-print 11 January 2007.
* Corresponding author. Tel: +45 38 16 43 24; fax: +45 38 16 43 59. E-mail address: morten.schou{at}fh.hosp.dk
Aims Here, the aim is to assess long-term clinical variation (CV) of N-terminal pro-brain natriuretic peptide (NT-proBNP) in stable chronic heart failure (CHF) patients. The proposed use of NT-proBNP for monitoring of CHF patients will require accurate information about long-term CV of the peptide.
Methods and results Medication, biochemical variables, and NYHA class were recorded at 1-year and 2-year follow-up in patients treated in our heart failure clinic. Only patients without changes in medication and the NYHA class who were not hospitalized or died in the period from first follow-up to 12 months after the second follow-up were included. A total of 78 patients fulfilled the criteria, and year-to-year CV was calculated to 30% (median) (range: 0–111%) (% changes range: –87 to 397%). Log transformation of NT-proBNP (skewed to the right) reduced the year-to-year CV to 4.7% (range: 0–22%) (% changes range: –18 to 38%).
Conclusion Long-term CV of plasma concentrations of NT-proBNP in stable CHF patients is 30%, but the variation is substantial. Therefore, high long-term CV of NT-proBNP does not necessarily carry prognostic significance within the subsequent 12 months. Plasma concentrations of NT-proBNP followed a lognormal distribution, and the low CV of log(NT-proBNP) indicate that NT-proBNP levels are constant during stable conditions.
Key Words: Chronic heart failure • Natriuretic peptides • Long-term variation