Atrial fibrillation — ABIM Board MCQ

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ModerateCardiovascularAtrial fibrillationABIM Board

A 78-year-old man with hypertension and a prior transient ischemic attack has palpitations. A 12-lead ECG obtained during symptoms shows atrial fibrillation, and subsequent ambulatory monitoring confirms a paroxysmal pattern. His creatinine clearance is 54 mL/min. He has no mechanical heart valve, moderate-to-severe mitral stenosis, contraindication to anticoagulation, or indication for antiplatelet therapy. Which of the following is the most appropriate management to prevent stroke?

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Correct answer: D — Apixaban

The correct answer is apixaban. His CHA2DS2-VASc score is 5—age 75 years or older, hypertension, and prior TIA—placing him at high thromboembolic risk and establishing a strong indication for oral anticoagulation. Stroke-prevention decisions are based on thromboembolic risk rather than whether atrial fibrillation is paroxysmal or persistent. In patients without a mechanical valve or moderate-to-severe mitral stenosis, a direct oral anticoagulant such as apixaban is preferred. His creatinine clearance is compatible with apixaban therapy. Aspirin and clopidogrel provide substantially less effective stroke prevention and are not recommended as substitutes for anticoagulation. No therapy would leave a high-risk patient unprotected. Left atrial appendage closure is not first-line when long-term anticoagulation is feasible; it is generally considered when anticoagulation is contraindicated or carries an unacceptably high bleeding risk.

Reference: American College of Cardiology/American Heart Association/American College of Clinical Pharmacy/Heart Rhythm Society. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation, antithrombotic therapy and left atrial appendage occlusion recommendations. 2023. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2023/11/27/19/46/2023-acc-guideline-for-af-gl-af