10 Things about the Cardiac Biomarker in Heart Failure

Heart failure (HF), also known as Congestive Cardiac Failure (CCF), is a condition that develops when the heart is unable to pump sufficient blood to fulfil the body’s needs. 

Blood tests can be carried out to detect a specific cardiac biomarker, the natriuretic peptides, that aids in the diagnosis of HF. This article tackles 10 things about cardiac biomarkers in heart failure.

1. Natriuretic peptides are made by the heart.

• They are released by cardiac muscles when they are stretched from having to work harder.  
• Levels tend to increase as HF develops.

2. Two main kinds of natriuretic peptides for HF that can be measured using blood tests: 

• Brain Natriuretic Peptide (BNP):

First identified within the brain, but released primarily from the heart.

• N-terminal Pro B-type Natriuretic Peptide (NT – proBNP):

The inactive form of BNP is produced at the same time. 

3. BNP is a type of hormone that can help control blood volume.

4. Recommended as the initial diagnostic test in patients suspected of having HF.

• Both the natriuretic peptides used in the diagnosis of HF are measured differently but ultimately provide the same information for the determination of HF in patients.
• Results are not interchangeable and cannot be compared directly with each other.
• Often, only either one will be tested for, depending on the healthcare provider’s laboratory.
• Results can also help to classify the urgency of the condition and guide subsequent therapeutic interventions. 

5. Other functions of the test: 

• Determination of the severity of the condition
• Formulation of a treatment plan
• Monitoring of therapeutic response

6. Under normal circumstances, low levels of both natriuretic peptides can be found in the bloodstream. 

• Therefore, usual serum concentrations of these typically exclude the diagnosis of HF, especially in an untreated patient. 
• Amounts detected can be disproportionately low in obese patients, and need to be interpreted with caution in these patient groups].  

7. Abnormally raised amounts usually reflect a diagnosis of HF.

• In general, the higher the levels, the greater the probability of HF.
• But further investigations (e.g., an echocardiogram) need to be conducted to confirm it.
• Elevated levels are also useful for prognostication as they tend to be associated with increased severity, and greater mortality.

8. Other potential causes for increased levels:

Cardiac related:

• Acute coronary syndrome
• Pulmonary embolism
• Myocarditis
• Valvular heart disease
• Congenital heart disease
• Heart surgery

Non-cardiac related: 

• Advanced age
• Certain brain conditions (e.g., stroke, haemorrhage)
• Kidney disease
• Liver disease
• Infections

9. Following diagnosis and therapy for HF, levels of BNP or NT pro-BNP can be reduced. 

• Concentrations will decrease along with the stabilization of HF. 

10. Levels can sometimes be affected by certain medications (e.g., ACE inhibitors, beta-blockers, and diuretics may reduce their concentrations). 

• Important to inform clinicians to ensure accurate evaluation of results is obtained. 

Conclusion:

BNP or NT pro-BNP are useful tools for the diagnosis and evaluation of patients with HF. But, their values have to be interpreted along with other clinical evidence to ensure a more accurate diagnosis as there are various factors and other conditions that can influence their levels in the bloodstream. It is therefore important to discuss, and inform your doctor of your medical history, to ensure that therapeutic decisions can be made more comprehensively.