A 42-year-old woman is evaluated for palpitations. She describes them as an occasional "fluttering in the chest" that is sometimes precipitated by emotion. Her lifestyle is sedentary, but she has had no shortness of breath, cough, or lower extremity swelling and no history of bleeding. The patient emigrated from Mexico when she was 6 years old. She is a lifetime nonsmoker and does not drink alcohol.
Blood pressure is 135/85 mm Hg. ECG shows a normal sinus rhythm with a heart rate of 65/min.
Resting transthoracic echocardiogram shows moderate left atrial dilation, mitral stenosis with a valve area of 1.5 cm², pliable leaflets with minimal calcification, mild mitral regurgitation, normal right ventricle size, and an estimated pulmonary artery systolic pressure of 25 mm Hg. Two episodes of atrial fibrillation lasting 20 minutes each are seen on 24-hour Holter monitoring.
What is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

This patient has paroxysmal atrial fibrillation (AF) in the setting of mitral stenosis, which carries an especially high risk of thromboembolic stroke. Current guidelines recommend long-term anticoagulation with warfarin (goal: INR of 2.5) to decrease the risk of systemic thromboembolism in all patients with mitral stenosis and 1 or more of the following: AF (paroxysmal, persistent, or permanent)Left atrial thrombusPrior embolic event AF (paroxysmal, persistent, or permanent) Left atrial thrombus Prior embolic event (Choice A) More recently developed oral anticoagulants, including oral factor Xa inhibitors (eg, rivaroxaban, apixaban, edoxaban) and direct thrombin inhibitors (eg, dabigatran), are approved only for patients with nonvalvular AF. Their use is not indicated in patients with mitral stenosis, prosthetic heart valves, or prior mitral valve repair. (Choice C) Aspirin has consistently been less effective than warfarin in preventing systemic thromboembolism in randomized trials of patients with AF, and current guidelines preferentially recommend warfarin over aspirin. (Choice D) The CHA₂DS₂VASc scoring system is routinely used for thromboembolic risk stratification in patients with nonvalvular AF. However, AF in the setting of mitral stenosis carries high thromboembolic risk regardless of age or underlying comorbidity, and the CHA₂DS₂VASc scoring system is not applicable. CHA₂DS₂VASc (Choice E) Transesophageal echocardiography can be used to visualize left atrial appendage thrombus. However, this patient is at high risk of thromboembolic stroke and requires anticoagulation with warfarin regardless of whether atrial thrombus is currently present. Educational objective: Patients with mitral stenosis and atrial fibrillation (paroxysmal, persistent, or permanent) are at high risk of thromboembolic stroke and should receive long-term anticoagulation with warfarin. More recently developed oral anticoagulants (factor Xa inhibitors and direct thrombin inhibitors) are not approved for use in patients with valvular atrial fibrillation. __________ References: Antithrombotic and thrombolytic therapy for valvular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/22315272) 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/24603191)

A 42-Year-Old Woman Is Evaluated for Palpitations