Clinical biochemistry: NT-proBNP with sacubitril: practice question

A Biochemistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Biochemistry · Clinical biochemistry: NT-proBNP with sacubitril

Sample item

A man with chronic heart failure is switched from valsartan to sacubitril-valsartan. His BNP rises after the change though he feels better. Which biomarker is preferred for monitoring him, and why?

ANT-proBNP, because neprilysin does not degrade itBTroponin T, because it falls with neprilysin inhibitionCProcalcitonin, because it reflects ventricular wall stressDBNP, because neprilysin degrades it faster on the drug

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. NT-proBNP, because neprilysin does not degrade it

Neprilysin degrades BNP, so inhibiting it raises BNP levels independent of the clinical state. NT-proBNP, the inactive fragment cleaved from proBNP, is not a neprilysin substrate and remains a valid marker of wall stress. BNP and NT-proBNP are both released from ventricular myocytes in response to stretch.

Option by option

A. NT-proBNP, because neprilysin does not degrade it (correct)
Correct. NT-proBNP is not cleared by neprilysin and so is unaffected by the drug.
B. Troponin T, because it falls with neprilysin inhibition
Troponin T reflects myocyte injury and is not a measure of wall stress in heart failure.
C. Procalcitonin, because it reflects ventricular wall stress
Procalcitonin is a marker of bacterial infection and not of ventricular wall stress.
D. BNP, because neprilysin degrades it faster on the drug
Neprilysin inhibition slows BNP degradation, so BNP rises falsely and is a poor marker here.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is A, NT-proBNP, because neprilysin does not degrade it. Neprilysin degrades BNP, so inhibiting it raises BNP levels independent of the clinical state.

Why is "Troponin T, because it falls with neprilysin inhibition" not the answer?

Troponin T reflects myocyte injury and is not a measure of wall stress in heart failure.

Why is "Procalcitonin, because it reflects ventricular wall stress" not the answer?

Procalcitonin is a marker of bacterial infection and not of ventricular wall stress.

Why is "BNP, because neprilysin degrades it faster on the drug" not the answer?

Neprilysin inhibition slows BNP degradation, so BNP rises falsely and is a poor marker here.

What concept does this question test?

It tests Clinical biochemistry: NT-proBNP with sacubitril in Biochemistry. NT-proBNP, the inactive fragment cleaved from proBNP, is not a neprilysin substrate and remains a valid marker of wall stress. BNP and NT-proBNP are both released from ventricular myocytes in response to stretch.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Clinical biochemistry: NT-proBNP with sacubitril?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.