BNP/NT-proBNP Ratio Index: Explanation and Clinical Context The BNP/NT-proBNP Ratio Index provides additional insight into the biochemical phenotype of heart failure and helps to differentiate between acute and chronic heart failure presentations. Both BNP and NT-proBNP are derived from proBNP, but they differ in clearance mechanisms and biological half-life. BNP is biologically active and cleared mainly by natriuretic peptide receptors and enzymatic degradation, while NT-proBNP is biologically inert and cleared primarily via renal filtration.
A low ratio (<0.20) typically indicates acute decompensated heart failure or renal dysfunction, where NT-proBNP levels are disproportionately elevated due to decreased renal clearance. A mid-range ratio (0.20–0.40) suggests chronic compensated heart failure, whereas a high ratio (>0.40) may be observed in patients with preserved ejection fraction (HFpEF), elderly individuals, or conditions with less renal involvement.
Recent studies have highlighted that BNP/NT-proBNP ratio can refine diagnostic accuracy when interpreting natriuretic peptide results, especially in settings where eGFR, body composition, and age influence NT-proBNP levels disproportionately.
Clinical Significance:
This ratio supports differential interpretation of natriuretic peptides, improving the diagnostic and prognostic precision in heart failure evaluation. It may be particularly helpful when NT-proBNP levels appear elevated out of proportion to clinical severity.
Clinical Interpretation Summary:
- <0.20 → Suggestive of acute decompensated HF / renal dysfunction
- 0.20–0.40 → Consistent with chronic stable HF
- >0.40 → Possible HFpEF or preserved systolic function pattern
References:
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2. Bay M, et al. Clin Chem. 2003;49(4):583–590. doi:10.1373/49.4.583
3. Januzzi JL Jr, et al. J Am Coll Cardiol. 2005;45(7):1101–1109. doi:10.1016/j.jacc.2004.12.056