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Device-detected atrial fibrillation with rheumatic mitral stenosis — ABIM Board MCQ

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HardRecommendationsDevice-detected atrial fibrillation with rheumatic mitral stenosisABIM Board

A 72-year-old woman with hypertension, type 2 diabetes mellitus, and rheumatic mitral stenosis is evaluated after routine pacemaker interrogation. She has no palpitations, prior stroke, or previously diagnosed atrial fibrillation. The device recorded an atrial high-rate episode lasting 26 hours. Review of the stored intracardiac electrogram confirms atrial fibrillation rather than artifact or another atrial tachyarrhythmia. Echocardiography shows a mitral valve area of 1.3 cm² and moderate left atrial enlargement. Her estimated glomerular filtration rate is 68 mL/min/1.73 m². She has no history of major bleeding, and her platelet count and liver biochemical tests are normal. After discussion of the potential benefits and harms, she prioritizes stroke prevention and accepts regular laboratory monitoring. Which of the following is the most appropriate management strategy?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: C — Initiate warfarin with a target INR of 2.0–3.0

Explanation lettering: C = shown as A · A = shown as B · B = shown as C

This patient should begin warfarin with a target INR of 2.0–3.0. The intracardiac electrogram confirms a device-detected atrial high-rate episode lasting at least 24 hours. With a CHA₂DS₂-VASc score of 4 (hypertension, diabetes, age 65–74 years, and female sex), initiation of oral anticoagulation is reasonable after shared decision-making. Her preference for stroke prevention and absence of a major bleeding contraindication favor treatment. The anticoagulant must then be selected according to her valve disease. A mitral valve area of 1.3 cm² indicates clinically significant rheumatic mitral stenosis; in this setting, warfarin is recommended over direct oral anticoagulants. Therefore, apixaban (A), although generally preferred for nonvalvular atrial fibrillation, is inappropriate here. Aspirin (C) is not an effective substitute for indicated anticoagulation. Surface electrocardiographic confirmation (D) is unnecessary after clinician review confirms the nature and duration of the device-recorded episode. Percutaneous left atrial appendage occlusion (E) is primarily an alternative for selected patients who have a contraindication to long-term anticoagulation or an exceptionally high bleeding risk; neither is present in this patient.

Reference: 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation (2023; journal issue January 2024) — https://www.heart.org/-/media/Files/Professional/Quality-Improvement/Get-With-the-Guidelines/Get-With-The-Guidelines-AFIB/AFib-Month/joglaretal20232023accahaaccphrsguidelineforthediagnosisandmanagementofatrialfibrillation.pdf 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation (2023; journal issue January 2024) — https://www.heart.org/-/media/Files/Professional/Quality-Improvement/Get-With-the-Guidelines/Get-With-The-Guidelines-AFIB/AFib-Month/joglaretal20232023accahaaccphrsguidelineforthediagnosisandmanagementofatrialfibrillation.pdf Rivaroxaban in Rheumatic Heart Disease–Associated Atrial Fibrillation (August 27, 2022) — https://www.nejm.org/doi/full/10.1056/NEJMoa2209051