Can elevated Brain Natriuretic Peptide (BNP) represent Pulmonary Embolism (PE)?

From the Guidelines

Elevated BNP levels can indeed represent pulmonary embolism (PE), particularly in patients with higher risk and more severe cases. BNP is primarily known as a marker of heart failure, but it can also be elevated in patients with acute PE, due to right ventricular strain caused by the pulmonary vascular obstruction, which triggers BNP release from cardiac myocytes in response to increased wall tension 1. The study by the European Heart Journal suggests that BNP values < 50 or 90 ng/L identify low-risk patients, while high-risk patients have values > 500 ng/L 1.

Key Points to Consider

• Elevated BNP levels are associated with worse outcomes in PE patients, including increased mortality and need for escalation of care 1.
• BNP elevation is not specific to PE and can occur in many other conditions affecting the heart, including heart failure, myocardial infarction, and atrial fibrillation.
• The use of echocardiography in patients with high BNP values is useful to identify a high-risk subset 1.
• Persistent elevations of NT-proBNP indicate right ventricular dysfunction and a poor prognosis 1.

Clinical Implications

• While elevated BNP can support a PE diagnosis in the appropriate clinical context, it should not be used alone for diagnosis but rather as part of a comprehensive assessment including clinical probability scoring, D-dimer testing, and appropriate imaging studies like CT pulmonary angiography.
• BNP levels should be interpreted in conjunction with other clinical and diagnostic findings to accurately diagnose and manage PE.

From the Research

Elevated BNP and Pulmonary Embolism

Elevated brain-type natriuretic peptide (BNP) levels can be associated with pulmonary embolism (PE), particularly in patients at higher risk of complicated in-hospital course and death 2.

Association with Right Ventricular Dysfunction

• Elevated BNP or N-terminal-pro-BNP (NT-pro-BNP) levels are significantly associated with right ventricular dysfunction (P < 0.001) 2.
• Right ventricle dysfunction (RVD) assessed by echocardiography, computed tomography, or elevated BNP/NT-proBNP levels is associated with short-term death in patients with acute PE at low risk based on clinical models 3.
• Pro-ANP, BNP, and D-dimer are associated with significantly elevated levels in PE patients with RVD 4.

Diagnostic Value

• Elevated BNP levels can distinguish patients with pulmonary embolism at higher risk of complicated in-hospital course and death from those with low BNP levels 2.
• BNP/NT-proBNP or echocardiography should be considered to improve identification of low-risk patients that may be candidates for outpatient management or short hospital stay 3.
• However, increased BNP or NT-pro-BNP concentrations alone do not justify more invasive treatment regimens 2.

Comparison with Other Diagnostic Tests

• D-dimer assay has high sensitivity but low specificity for diagnosing PE, while computed tomography pulmonary angiography (CTPA) and ventilation-perfusion (V/Q) scanning have high specificity but lower sensitivity 5.
• The diagnostic value of elevated BNP in PE should be considered in conjunction with other clinical and diagnostic factors, such as clinical decision rules and imaging studies 6.