Which test is commonly used as a biomarker to differentiate heart failure–related dyspnea from other causes?

• A. BNP or NT-proBNP testing
• B. Echocardiography
• C. Chest X-ray
• D. Jugular venous pressure assessment

Answer: (A)

A circulating peptide biomarker that rises with heart-wall stress helps separate heart failure–related shortness of breath from non-cardiac causes. BNP and its inactive counterpart, NT-proBNP, are released by the ventricles when they are stretched by pressure or volume overload. In heart failure, levels climb because the heart is under strain; when dyspnea stems from non-cardiac problems like a lung infection or COPD, these levels are usually normal or only mildly elevated. Because of this, measuring BNP or NT-proBNP is a quick way to support or refute cardiac involvement early in the evaluation.

In practice, a normal BNP or NT-proBNP makes heart failure unlikely and steers the clinician toward non-cardiac etiologies, while elevated levels prompt further cardiac assessment, typically with echocardiography to evaluate heart structure and function. Interpretation should consider factors that can alter levels, such as age, obesity (which can lower BNP), renal function, and other conditions like atrial fibrillation or sepsis, which can raise levels independently of HF. This biomarker is especially useful for ruling out HF in acute dyspnea and guiding downstream testing and management.