Testing for NTproBNP or BNP in the Diagnosis of HFpEF

This transcript has been edited for clarity.

BNP (B-type natriuretic peptide) or NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels can be elevated in patients with heart failure with preserved EF (ejection fraction; HFpEF), as well as in heart failure with reduced EF, and correlated with severity of heart failure. But the levels interestingly are lower in patients with HFpEF compared to those with heart failure with reduced EF.^[1] We need to keep in mind that though the higher levels are helpful in supporting the diagnosis of patients with HFpEF, lower levels may not always rule out the presence of patients with HFpEF.

In patients with HFpEF, elevated filling pressures or myocardial wall stress may be apparent after exercise, but not at rest. Also, comorbidities such as lung disease, atrial fibrillation, chronic kidney disease, hypertension, obesity are very common in patients with HFpEF.^[2,3] Most of these entities can mimic the symptoms of heart failure, and therefore, the natriuretic peptide levels can help in the setting of diagnostic uncertainty in patients with HFpEF, especially when the patient is presenting with symptoms of dyspnea and has comorbidity of chronic lung disease.

But we also need to keep in mind, women tend to have slightly higher levels of natriuretic peptide levels than men.^[4,5] Older patients, patients with atrial fibrillation, patients with CKD (chronic kidney disease) have higher levels.^[6] Therefore, the thresholds for diagnosis or exclusion of such patients with HFpEF will need to be adjusted according to age, presence of these comorbidities, and gender. And obesity, which is a common comorbidity in patients with HFpEF, is associated with lower natriuretic peptide levels.^[7] Thus, these comorbidities and patient phenotypes—age, gender, race—are critical to determine the background contribution of these factors on natriuretic peptide levels when taking these into consideration for diagnosis or exclusion of patients with HFpEF.