Which statement about B-type natriuretic peptide (BNP) is true in the context of heart failure?

• A. BNP levels always fall after treatment in diastolic dysfunction
• B. ≥100 pg/mL suggests HF
• C. BNP never rises with aging
• D. BNP can be elevated in other conditions

Answer: (B)

BNP is released by ventricular cells in response to increased wall stretch from volume or pressure overload, so levels rise in heart failure. In practice, a BNP level at or above about 100 pg/mL is a commonly used threshold that suggests heart failure when a patient presents with dyspnea or suspected HF. This cutoff provides a straightforward, clinically useful clue that HF is likely, guiding further evaluation like echocardiography. While this statement is the most directly diagnostic, other points are true in certain contexts but less definitive: BNP can decrease with treatment in some cases but not reliably, especially with diastolic dysfunction; BNP can rise with aging; and BNP can be elevated in several other conditions such as renal failure or sepsis. The 100 pg/mL threshold remains the best single indicator for HF suspicion in the right clinical setting.