Which of the following cardiac markers is the most useful indicator of congestive heart failure?

• A. BNP
• B. TnI
• C. CK-MB
• D. Glycogen phosphorylase isoenzyme BB

Answer: (A)

BNP rises when the ventricles are stretched from volume or pressure overload, so it directly reflects the state of heart failure. In congestive heart failure, increased filling pressures cause the ventricles to release BNP, which then acts to promote natriuresis and vasodilation, helping to reduce preload and afterload. Because its level correlates with the degree of ventricular wall stress, BNP provides both diagnostic and prognostic information about heart failure and can help distinguish dyspnea due to heart failure from other causes.

The other markers indicate different processes. Troponin I signals myocardial injury (such as a heart attack), CK-MB likewise reflects myocardial damage, and glycogen phosphorylase isoenzyme BB has a less specific role in ischemia-related contexts. They don’t specifically measure ventricular stretch or heart-failure severity, which is why BNP is the most useful indicator in congestive heart failure.