From the Guidelines
Elevated N-terminal pro b-type natriuretic peptide (NT pro BNP) levels are primarily caused by cardiac conditions such as heart failure, acute coronary syndromes, and valvular heart disease, as well as non-cardiac conditions like pulmonary embolism, sepsis, and renal failure, as outlined in the 2016 ESC guidelines 1. The causes of elevated NT pro BNP can be broadly categorized into cardiac and non-cardiac conditions. Cardiac causes include:
- Heart failure
- Acute coronary syndromes
- Pulmonary embolism
- Myocarditis
- Left ventricular hypertrophy
- Hypertrophic or restrictive cardiomyopathy
- Valvular heart disease
- Congenital heart disease
- Atrial and ventricular tachyarrhythmias Non-cardiac causes include:
- Advanced age
- Ischaemic stroke
- Subarachnoid haemorrhage
- Renal dysfunction
- Liver dysfunction (mainly liver cirrhosis with ascites)
- Paraneoplastic syndrome
- Chronic obstructive pulmonary disease
- Severe infections (including pneumonia and sepsis)
- Severe burns
- Anaemia
- Severe metabolic and hormone abnormalities It is essential to note that NT pro BNP levels can be influenced by various factors, including comorbidities, medications, and laboratory measurements, as discussed in the 2017 American Heart Association scientific statement 1. The diagnosis and management of elevated NT pro BNP levels should be guided by the underlying cause, with consideration of cardiac and non-cardiac conditions, as well as the patient's overall clinical presentation and laboratory results 1.
From the Research
Causes of Elevated NT pro BNP
The causes of elevated N-terminal pro b-type natriuretic peptide (NT pro BNP) are varied and can be attributed to several factors, including:
- Heart diseases such as heart muscle disease, valve disease, rhythm abnormalities, pulmonary hypertension, and cytotoxic injury to the heart 2
- Non-cardiac conditions like gram-negative sepsis 2
- Critical illness, including acute respiratory distress syndrome, sepsis, and renal dysfunction 3, 4
- Pulmonary diseases such as acute pulmonary embolism, chronic obstructive pulmonary disease 4
- Acute coronary syndromes, including ST-elevation and non-ST-elevation ACS 5
- Congestive heart failure (CHF) 6
Disease Processes Associated with Elevated NT pro BNP
Elevated NT pro BNP levels have been observed in various disease processes, including:
- Heart failure (HF) 2, 6
- Acute coronary syndromes (ACS) 5
- Pulmonary hypertension 2, 4
- Acute respiratory distress syndrome (ARDS) 3, 4
- Sepsis 2, 3
- Renal dysfunction 3, 4
- Acute pulmonary embolism (APE) 6
Clinical Significance of Elevated NT pro BNP
Elevated NT pro BNP levels are often associated with adverse outcomes, including increased risk of mortality 3, 5. Therefore, it is essential to consider the clinical context and underlying disease processes when interpreting NT pro BNP levels, rather than dismissing them as "false-positive" findings 2.