From the Guidelines
NT-proBNP levels above 450 pg/mL for patients under 50 years, above 900 pg/mL for those 50-75 years, and above 1800 pg/mL for those over 75 years are considered significant for diagnosing heart failure, as indicated by the most recent and highest quality study 1.
Key Considerations
- For acute settings, levels exceeding 300 pg/mL suggest heart failure or pulmonary edema, while levels below 100 pg/mL effectively rule out these conditions 1.
- The threshold varies with age because NT-proBNP naturally increases as people get older.
- These biomarkers are released when cardiac muscle is stretched due to volume or pressure overload, making them valuable diagnostic tools.
Clinical Context
- Interpretation should always consider clinical context, as other conditions like renal dysfunction, sepsis, and advanced age can elevate NT-proBNP without heart failure 1.
- For optimal assessment, NT-proBNP results should be evaluated alongside physical examination findings, patient symptoms, and imaging studies like echocardiography to confirm the diagnosis and determine appropriate treatment.
Diagnostic Thresholds
- The diagnostic strength of natriuretic peptides is their high sensitivity for ruling out HF; however, as the value increases, HF becomes more likely 1.
- Proposed rule-in cutoffs are the age-related values presented above for NT-proBNP and a value >400 pg/mL for BNP 1.
Limitations and Caveats
- The accuracy of natriuretic peptides for the detection of HF is reduced in the setting of atrial fibrillation and sepsis, and careful interpretation is warranted 1.
- Concentrations of BNP or NT-proBNP can also be lower than expected in the setting of presumed AHF, particularly in obese patients 1.
From the Research
Pro-Brain Natriuretic Peptide (proBNP) Levels and Congestive Heart Failure (CHF) or Pulmonary Edema
- proBNP levels can be used to diagnose and predict congestive heart failure (CHF) and pulmonary edema 2, 3, 4, 5, 6
- A cut-off value of NT-proBNP at > 150 pg/ml can be used to diagnose HF in patients with dyspnea, with a sensitivity of 96% and specificity of 72% 2
- A cut-off value of NT-proBNP at > 200 pg/ml can be used to diagnose HF in patients with dyspnea, with a sensitivity of 96% and specificity of 80% 2
- A cut-off value of NT-proBNP at > 300 pg/ml can be used to diagnose HF in patients with dyspnea, with a sensitivity of 94% and specificity of 82% 2
- NT-proBNP levels above 5000 pg/ml are associated with a higher mortality rate in patients with CHF 4
- An NT-proBNP cutoff level <300 pg/ml can be used to rule out acute CHF, with a negative predictive value of 96% and sensitivity of 96% 5
- NT-proBNP levels > 1958 pg/ml are associated with a higher risk of mortality in patients with CHF, with a sixfold risk of early death 6
- A single high NT-proBNP measurement > 550 pg/ml can be used to select patients for care in a heart failure center, and a level > 2000 pg/ml for assigning patients to high priority management 6
NT-proBNP Levels and Pulmonary Edema
- Serum NT-pro-BNP level > 6980 mg/dl is associated with the existence of cardiogenic pulmonary edema (CPE) in heart failure patients 3
- A novel NT-pro BNP-based scoring system containing risk factors such as serum NT-pro-BNP level, systemic blood pressure, heart rate, and others can be used to predict CPE in HF patients 3