Based on the 2014 ACC/AHA/HRS guidelines,1 all patients with atrial fibrillation (AF) should be stratified for risk of thrombosis and bleeding before the decision is made to initiate oral anticoagulation (OAC). The recommendation is that OAC should be started for any patient with a CHA2DS2-Vasc score ≥ 2. But, for reasons those of us in clinical practice know all too well, this doesn’t always happen. And, even in those patients who do get started on OAC, the long-term compliance (given that this is essentially “lifelong” therapy) is variable.
Case: Mrs Russell is a 74-year-old female with type 2 diabetes and hypertension who presented with paroxysmal atrial fibrillation during a recent influenza infection. She is active but lives on her own in a retirement community and does not drive. Today, she is in normal sinus rhythm at 78 beats/min and her blood pressure is 128/74 mm Hg. Her CHA2DS2-Vasc score is 3 (1 point each for female, HTN, DM). You counsel her on her indication for anticoagulation therapy and discuss the pros and cons of warfarin and the direct oral anticoagulants (DOACs). After a long discussion, where she tells you that she cannot afford DOACs, you decide to start warfarin, even though you realize it will be difficult for her to get to regular INR checks.
Question 1. Of those patients with newly-diagnosed AF who are eligible for and prescribed OAC, what percentage of patients stop taking VKA and what percentage stop taking DOACs at 2 years in real-world practice?
A. ~50% of those on VKA; ~50% of those on DOAC
B. ~30% of those on VKA; ~30% of those on DOAC
C. ~50% of those on VKA; ~30% of those on DOAC
D. ~30% of those on VKA; ~50% of those on DOAC
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1. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation. 2014;130:e199-e267
2. Martinez C, Katholing A, Wallenhorst C, Freedman SB. Therapy persistence in newly diagnosed non-valvular atrial fibrillation treated with warfarin or NOAC. A cohort study. Thromb Haemost. 2016;115:31-9. doi: 10.1160/TH15-04-0350. Epub 2015 Aug 6.
3. Holmes DR Jr, Kar S, Price MJ, et al. Prospective randomized evaluation of the Watchman Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy: the PREVAIL trial. J Am Coll Cardiol. 2014;64:1-12. doi: 10.1016/j.jacc.2014.04.029.