Which statements best describe two markers for congestive heart failure used clinically?

• A. BNP and NT-proBNP
• B. Troponin I and CK-MB
• C. Myoglobin and BNP
• D. C-reactive protein and D-dimer

Answer: (A)

The key idea is that two markers used clinically for heart failure are natriuretic peptides released by the heart in response to increased wall stress. When the ventricles are stretched by volume or pressure overload, they release B-type natriuretic peptide (BNP) and its inactive fragment (NT-proBNP). Measuring these in the blood helps confirm heart failure in a patient with dyspnea and also provides information about the severity and prognosis—the higher the levels, typically the more significant the heart failure.

BNP and NT-proBNP have practical differences: BNP is the active peptide with a shorter half-life, while NT-proBNP is more stable and has a longer half-life. In clinical use, either marker supports the diagnosis of congestive heart failure and helps differentiate it from non-cardiac causes of shortness of breath. Levels can be influenced by factors such as age, renal function, obesity, and atrial fibrillation, but the overall utility remains strong for HF assessment and management decisions.

The other listed markers do not specifically reflect heart failure. Troponin I and CK-MB indicate myocardial injury rather than ventricular stretch or filling pressures. Myoglobin is an injury marker for muscle tissue. C-reactive protein and D-dimer relate to inflammation and coagulation, not to heart failure physiology.