Cardiology: prosthetic valve anticoagulation: practice question

A General Medicine 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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General Medicine · Cardiology: prosthetic valve anticoagulation

Sample item

A 44-year-old woman has had a mechanical mitral valve replacement for rheumatic mitral disease and now has atrial fibrillation. Which anticoagulant strategy is appropriate?

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

The answer and the reasoning

A. Warfarin with a target INR of about 3.0

Mechanical heart valves require vitamin K antagonists, with a higher INR target for mitral than for aortic positions (about 3.0, range 2.5 to 3.5, for mitral). Direct oral anticoagulants are contraindicated in these patients, since dabigatran caused more thromboembolic and bleeding events than warfarin in the RE-ALIGN trial. Antiplatelet therapy alone is inadequate.

Option by option

  • A. Warfarin with a target INR of about 3.0 (correct)

    Warfarin is the only anticoagulant class proven and recommended for mechanical valves.

  • B. Rivaroxaban at the standard dose

    Direct factor Xa inhibitors are not approved for mechanical valves and have no adequate evidence.

  • C. Dabigatran at the standard dose

    Dabigatran was inferior and harmful in mechanical valve patients.

  • D. Aspirin alone

    Aspirin does not give enough protection against valve thrombosis and embolic stroke.

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.

More General Medicine questions

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is A, Warfarin with a target INR of about 3.0. Mechanical heart valves require vitamin K antagonists, with a higher INR target for mitral than for aortic positions (about 3.

Why is "Rivaroxaban at the standard dose" not the answer?

Direct factor Xa inhibitors are not approved for mechanical valves and have no adequate evidence.

Why is "Dabigatran at the standard dose" not the answer?

Dabigatran was inferior and harmful in mechanical valve patients.

Why is "Aspirin alone" not the answer?

Aspirin does not give enough protection against valve thrombosis and embolic stroke.

What concept does this question test?

It tests Cardiology: prosthetic valve anticoagulation in General Medicine. 0, range 2.5 to 3.5, for mitral). Direct oral anticoagulants are contraindicated in these patients, since dabigatran caused more thromboembolic and bleeding events than warfarin in the RE-ALIGN trial. Antiplatelet therapy alone is inadequate.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Cardiology: prosthetic valve anticoagulation?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.