The Role of Natriuretic Peptides

“ [BNP and NTproBNP] may be more useful clinically as a rule out test due to consistent and very high negative predictive values.”

Task Force for the Diagnosis and Treatment of Chronic Heart Failure, European Society of Cardiology. European Heart Journal. 2001.²

Plasma concentrations of certain natriuretic peptides can be helpful in the diagnostic process, especially in untreated patients. Several clinical and epidemiological studies have related decreasing cardiac, usually left, ventricular function with increasing plasma natriuretic peptide concentrations, raising the possibility of a diagnostic blood test for heart failure.²

Measurement of circulating levels of brain natriuretic peptides (BNP or NT-proBNP) provide a means of identifying patients with elevated left ventricular filling pressures who are likely to exhibit signs and symptoms of HF. While this is widely investigated as a biochemical marker of morbidity and mortality in patients with known HF, and as an aid in differentiating dyspnea due to HF from dyspnea due to other causes in an emergency setting, these assays cannot reliably distinguish patients with systolic dysfunction from those with diastolic dysfunction.¹

High levels of natriuretic peptides identify those at greatest risk of future serious cardiovascular events, including death. There is also recent evidence that adjusting heart failure therapy in order to reduce natriuretic peptides levels in individual patients may improve outcomes. In addition, these peptides may be more useful clinically as a rule out test due to consistent and very high negative predictive values.²

The cardiac ventricles are the major source of plasma BNP and NT-proBNP. In general, plasma BNP and NT-proBNP levels correlate positively with the degree of left ventricular dysfunction, but they are sensitive to other biological factors such as age, sex, and diastolic dysfunction. Clinical experience suggests that BNP and NT-proBNP may have utility in the urgent care setting, where it has been used to differentiate dsypnea due to HF from pulmonary disease with acceptable sensitivity and specificity. They may also be useful in managing patients with HF, but more research will be necessary to determine its role in both diagnosis and management.¹

Patients suspected of having HF, especially in primary care settings, can be selected for further investigation by echocardiography or other tests of cardiac function on the basis of having an elevated plasma concentration of natriuretic peptide. In those in whom the concentrations are normal, other causes of dyspnea and associated symptoms should be considered.²

For more information, click on the following subject:
Clinical Assessment of Patients with Heart Failure
Identification of a Structural Abnormality
Evaluating the Cause of Ventricular Dysfunction
The Role of Natriuretic Peptides

References