Reference Values

For patients presenting to ED settings with clinical suspicion of HF, the PBNPII assay results should be interpreted as indicated below.

All age groups:  < 300 pg/mL -  Negative: Heart Failure Unlikely

< 50 years:        ≥ 300 - ≤ 450 pg/mL  -  Gray Zone: Result Indeterminate - Consider other reasons for NT-proBNP elevation

50-75 years:      ≥ 300 - ≤ 900 pg/mL  -  Gray Zone: Result Indeterminate - Consider other reasons for NT-proBNP elevation

>75 years:         ≥ 300 - ≤ 1800 pg/mL -  Gray Zone: Result Indeterminate - Consider other reasons for NT-proBNP elevation

< 50 years:      >450 pg/mL    -    Positive: Heart Failure Likely

50-75 years:    >900 pg/mL    -    Positive: Heart Failure Likely

>75 years:       >1800 pg/mL   -   Positive: Heart Failure Likely

In outpatient settings, the optimal use of natriuretic peptide assays exclude the HF diagnosis. Therefore, a lower negative cut-off value which increases sensitivity and negative predictive value is needed, as these patients can present with limited, less acute HF symptoms.

For ambulatory patients presenting to outpatient facilities with clinical suspicion of HF not previously diagnosed, the PBNPII assay results should be interpreted as indicated below.

All age groups:  <125 pg/mL - Negative: Heart Failure Unlikely

All age groups:  ≥125 pg/mL - Consider Heart Failure as well as other causes of NT-proBNP elevation.* 

*Clinical conditions such as acute coronary syndrome, atrial fibrillation, pulmonary embolism, valvular heart disease, myocarditis, pulmonary hypertension, renal defieciency, stroke, and sepsis can elevate NT-proBNP levels in the absence of heart failure.