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• Plasma N-terminal-pro-brain natriuretic peptide as a useful biomarker for predicting all-cause death in patients with heart failure regardless of the levels of left ventricular ejection fraction
  Tomoyuki Kawada
  Published on: 21 September 2015

• Published on: 21 September 2015

  Plasma N-terminal-pro-brain natriuretic peptide as a useful biomarker for predicting all-cause death in patients with heart failure regardless of the levels of left ventricular ejection fraction

  • Tomoyuki Kawada, Professor

  I read with great interest the report by Kang et al., (1) who conducted one-year prospective study in 1670 patients with heart failure (HF). The authors measured plasma N-terminal-pro-brain natriuretic peptide (NT-proBNP), and left ventricular ejection fraction (LVEF) was used for binary classification of HF. Although patients with keeping LVEF showed significantly lower NT-proBNP level than those with reduced LVEF, all-...

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  I read with great interest the report by Kang et al., (1) who conducted one-year prospective study in 1670 patients with heart failure (HF). The authors measured plasma N-terminal-pro-brain natriuretic peptide (NT-proBNP), and left ventricular ejection fraction (LVEF) was used for binary classification of HF. Although patients with keeping LVEF showed significantly lower NT-proBNP level than those with reduced LVEF, all- cause death did not differ between two groups. In addition, plasma NT- proBNP and obesity were significant predictors of all-cause death regardless of the levels of LVEF. I have some concerns on their study.

  First, the authors selected the Cox proportional hazard model using forward selection method (Wald statistic) with 20 independent variables for predicting all-cause mortality. As LVEF was not selected as a significant variable, and Kaplan-Meier survival curves, stratified by LVEF, have small meaning in their study. Instead, the effect of obesity on all-cause death should be speculated. I suspected that obesity at baseline was partly caused by edema, although there was a decreasing trend of body mass index as plasma NT-proBNP increased. It seems appropriate that the authors selected body mass index instead of body fat mass as the indicator of obesity. On this point, further consideration is needed.

  Second, the authors conducted receiver operating characteristic curve analysis for predicting all-cause of death by using four models. I understand the disadvantage of model 1 with LVEF3, and model 2 with plasma NT-proBNP seems satisfactory for predicting all-cause of death. But model 3 with 5 clinical factors is also useful for the prediction. I suppose that body mass index would contribute for the statistical result.

  Their study presented that only use of LVEF for predicting all-cause death in patients with HF has a risk in clinical procedure. Although the authors explained one reference as presenting a tendency towards potential harm for survival by NT-proBNP guided therapy, (2) I think that the study design differs between two studies. Anyway, I recommend the authors additional survival analysis by excluding data of death in early period of time from the baseline to avoid unsuspected reason of death.

  References

  1. Kang SH, Park JJ, Choi DJ, et al. Prognostic value of NT-proBNP in heart failure with preserved versus reduced EF. Heart 2015 Aug 28. doi: 10.1136/heartjnl-2015-307782

  2. Maeder MT, Rickenbacher P, Rickli H, et al. N-terminal pro brain natriuretic peptide-guided management in patients with heart failure and preserved ejection fraction: findings from the Trial of Intensified versus standard medical therapy in elderly patients with congestive heart failure (TIME-CHF). Eur J Heart Fail 2013;15:1148-56.

  Conflict of Interest:

  None declared

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  Conflict of Interest:
  None declared.

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