In this case of heart failure, which biomarker was elevated to support the diagnosis?

• A. BNP
• B. Troponin
• C. CK-MB
• D. D-dimer

Answer: (A)

BNP is released by the heart’s ventricles in response to increased wall tension from volume and pressure overload, which is a hallmark of heart failure. When the ventricles are stretched by excess filling pressures, they secrete B-type natriuretic peptide to help reduce that burden by promoting sodium and water loss and by causing vasodilation to lower preload and afterload. Because of this, BNP levels rise as heart failure worsens or becomes more hemodynamically significant, making it a useful biomarker to support the diagnosis and gauge severity in patients with suspected congestive heart failure. In contrast, troponin and CK-MM are markers of myocardial injury like a heart attack, and D-dimer indicates clot formation and breakdown, not heart failure. So the elevated BNP best fits the scenario of heart failure.