• Perioperative NT-proBNP is a prognostic indicator for post-surgical outcomes and can be used to identify high risk patients and plan care appropriately.

Cautions:
• Laboratory Reports provide age specific cutoff values indicating probability of Heart Failure in adults. These are not “normal” reference values.  See reference values section below.
• NT-proBNP is a marker of myocardial stress, as such may be elevated among patients with severe respiratory illnesses typically in the absence of elevated filling pressures or clinical heart failure. 
• NT-proBNP cannot identify the underlying cause of HF and, therefore, if elevated, must always be used in conjunction with cardiac imaging.
• NT-proBNP measurements should always be used in conjunction with all other clinical information.

Resources:

The Canadian Cardiovascular Society – Is it Heart Failure and What Should I Do?  88067 CCS - HF Eng 2021 REV10  https://ccs.ca/wp-content/uploads/2021/05/2021-HF-Gui-PG-EN-2.pdf  

References:

1. Ezekowitz JA, O'Meara E, McDonald MA, et al. 2017 Comprehensive update of the Canadian Cardiovascular Society Guidelines for the management of heart failure. Can J Cardiol. 2017;33(11):1342-1433.

2. Kozhuharov N, et al. Clinical effect of obesity on N-terminal pro-B-type natriuretic peptide cut-off concentrations for the diagnosis of acute heart failure. European Journal of Heart Failure (2022) 24, 1545–1554

3. Welsh P, et al. Reference Ranges for NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) and Risk Factors for Higher NT-proBNP Concentrations in a Large General Population Cohort. Circ Heart Fail. (2022) Oct;15(10):e009427.

4. Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery. Can J Cardiol 2017:22;17-32

Clinical Practice Change: NT-proBNP Testing

 
Age < 50 yr
300-450 pg/mL:  Heart Failure is possible, but other diagnoses should be considered.
> 450 pg/mL:  Consider Heart Failure or other cause of myocardial stress.  Elevation may be due to severe respiratory illnesses, including pulmonary embolism. Clinical correlation required.
 
Age 50 to 75 yr
300-900 pg/mL:  Heart Failure is possible, especially if NT-proBNP is > 450 pg/mL. Other diagnoses should be considered.
> 900 pg/mL: Consider Heart Failure or other cause of myocardial stress.  Elevation may be due to severe respiratory illnesses, including pulmonary embolism. Clinical correlation required
 
Age > 75 yr
300-1800 pg/mL:  Heart Failure is possible, especially if NT-proBNP > 900 pg/mL. Other diagnoses should be considered.
>1800 pg/mL: Consider Heart Failure or other cause of myocardial stress.  Elevation may be due to severe respiratory illnesses, including pulmonary embolism. Clinical correlation required.

Laboratory Reports provide age specific cutoff values indicating probability of Heart Failure in adults. These are not “normal” reference values.  In healthy individuals NT-proBNP results are dependent on age (young children and older adults have higher values), gender (females have higher values then males) and body size.

Patients with heart failure and obesity show lower than expected NT-proBNP results.

Method of Analysis: Roche Cobas Elecsys proBNP II (Immunoassay)

Reference(s): The 2014 Canadian Cardiovascular Society Heart Failure Management Guidelines Focus Update: Anemia, Biomarkers, and Recent Therapeutic Trial Implications. Moe G et al. Canadian Journal of Cardiology. 2015; 31: 3-16