Introduction
The NT-proBNP is an essential cardiac biomarker for the diagnosis and management of heart disease in dogs and cats. This peptide is released by heart cells in response to pressure overload or cardiac stress. Its measurement in the blood enables veterinarians to distinguish heart disease from respiratory problems, and to assess the severity of cardiac pathologies. This article explores the advantages of the NT-proBNP test and its use in veterinary practice to improve the diagnosis and monitoring of heart disease.
What is NT-proBNP?
Le BNP (B-type natriuretic peptide) is a hormone produced by cells in the atria and ventricles of the heart in response to stretch or pressure overload. The NT-proBNP is a more stable fragment of the BNP precursor, and its measurement can detect cardiac dysfunction before clinical signs are visible. High levels of NT-proBNP are observed in animals suffering from cardiomyopathy, d’congestive heart failure (CHF) or other heart diseases.
Indications for NT-proBNP testing in dogs and cats
The NT-proBNP assay is particularly useful in the following contexts:
1. Diagnosis of Congestive Heart Failure (CHF)
The NT-proBNP test helps to distinguish between signs of respiratory distress of cardiac origin (such as CHF) of primary respiratory conditions (bronchitis, asthma, etc.). For example:
- In dogs, an NT-proBNP levels above 1800 pmol/L strongly suggests heart failure.
- In cats, an NT-proBNP level above 270 pmol/L indicates cardiomyopathy cardiomyopathy.
2. Screening for occult cardiomyopathy
NT-proBNP is particularly useful in cats, where cardiac heart murmurs are not always present despite an underlying disease. The test can be used to identify asymptomatic cats suffering from hypertrophic cardiomyopathy (HCM). Studies have shown that NT-proBNP can differentiate healthy cats from those with occult HCM, with a threshold of >100 pmol/L with 100% specificity for HCM detection.
3. Monitoring and management of heart disease
The NT-proBNP test can also be used to monitor the progression of heart disease in dogs and cats. An increase in NT-proBNP levels may indicate a worsening heart condition, necessitating adjustment of treatment.
Advantages and limitations of NT-proBNP testing
Benefits
- Early diagnosis NT-proBNP can detect heart disease before the onset of obvious clinical signs, particularly in cats.
- Differentiating the causes of respiratory distress This test is invaluable in determining whether signs of respiratory distress in dogs and cats are due to heart failure or lung disease.
- Monitoring heart patients Veterinarians can use NT-proBNP to monitor disease progression and adjust treatments accordingly.
Limits
- Results not immediate A disadvantage of the NT-proBNP test is the 2-3 day delay in obtaining results, which may limit its usefulness in emergency situations.
- Influence of kidney disease Kidney disorders can distort test results, as they can increase NT-proBNP levels in the absence of heart disease.
Clinical application: Interpretation of results
NT-proBNP test results should be interpreted according to the following thresholds:
Cats:
- <100 pmol/L Very unlikely heart disease.
- 100-270 pmol/L Heart disease unlikely, but follow-up recommended.
- >270 pmol/L : Significant cardiomyopathy, requiring in-depth evaluation.
Dogs:
- <900 pmol/L Low probability that symptoms are related to heart failure.
- 900-1800 pmol/L Non-diagnostic results; further tests required.
- >1800 pmol/L High probability of congestive heart failure.
Conclusion
The NT-proBNP test is a valuable tool for veterinarians in the diagnosis and management of heart disease in dogs and cats. It helps to distinguish between cardiac and respiratory conditions, and to detect asymptomatic heart disease at an early stage. Although additional results and clinical interpretation are often required, this test significantly improves veterinarians’ ability to manage heart disease in their patients.
