Which factor would most likely cause NT-proBNP levels to be higher than expected in evaluating heart failure symptoms?

Which factor would most likely cause NT-proBNP levels to be higher than expected in evaluating heart failure symptoms?

• A. High albumin
• B. Low GFR
• C. High GFR
• D. Normal creatinine

Answer: (B)

NT-proBNP levels depend not only on cardiac stress but also on how quickly the peptide is cleared from the body. It is cleared primarily by the kidneys, so when kidney function is reduced (low GFR), clearance slows and NT-proBNP accumulates, leading to higher levels than would be expected for a given amount of heart failure symptoms. This is why a low GFR tends to raise NT-proBNP independent of the heart’s actual stress level. In contrast, better kidney function (high GFR) would clear it more efficiently and lower the level; a normal creatinine or factors like high albumin don’t directly cause the same rise in NT-proBNP.

NT-proBNP levels depend not only on cardiac stress but also on how quickly the peptide is cleared from the body. It is cleared primarily by the kidneys, so when kidney function is reduced (low GFR), clearance slows and NT-proBNP accumulates, leading to higher levels than would be expected for a given amount of heart failure symptoms. This is why a low GFR tends to raise NT-proBNP independent of the heart’s actual stress level. In contrast, better kidney function (high GFR) would clear it more efficiently and lower the level; a normal creatinine or factors like high albumin don’t directly cause the same rise in NT-proBNP.