Name a biomarker commonly used to diagnose heart failure and monitor prognosis, and what does its level indicate?

• A. CRP.
• B. BNP or NT-proBNP; higher levels suggest HF presence and worse prognosis; levels fall with effective therapy.
• C. Troponin I for HF presence.
• D. D-dimer.

Answer: (B)

Natriuretic peptides, especially BNP and its inactive fragment NT-proBNP, are used to diagnose heart failure and gauge prognosis. They’re released by the heart’s ventricles in response to increased wall stress and elevated filling pressures from fluid overload. A higher level supports the presence of heart failure and is associated with worse outcomes, because it reflects greater congestion and myocardial strain. Importantly, levels tend to fall when effective therapy reduces congestion and improves hemodynamics, making them useful for monitoring response to treatment.

Some factors can modify these levels (age, renal function, obesity, and other acute illnesses). While helpful, these markers must be interpreted in the clinical context. In contrast, CRP is a marker of inflammation and is not HF-specific; troponin I signals myocardial injury rather than chronic HF presence or prognosis; D-dimer relates to clot formation and breakdown, not HF diagnosis or prognosis.