AFib treatment: general population

When primary care physicians are presented with a patient with atrial fibrillation (AFib), there are two concerns. (online video available at: http://education.amjmed.com/video.php?event_id=445&stage_id=5&vcs=1). One is the choice of strategy to treat the AFib, ie, whether to use rate control or a rhythm control strategy (to keep patients in sinus rhythm). The second concern is preventing the principal risk associated with AFib: stroke and systemic embolism. The focus of this review is stroke prevention, concentrating on risk assessment and traditional versus the new oral anticoagulation agents. For the past several decades, oral anticoagulation therapy has meant warfarin, which has the benefit of >50 years of clinical experience: it is inexpensive, it has generic availability, and it has a wide range of clinical use indications beyond merely stroke prophylaxis in patients with AFib. On the other hand, only about half of the patients who should be receiving warfarin are prescribed it (and even fewer older patients are prescribed it), and only 30% of patients maintain time in therapeutic range (TTR) for serum warfarin levels at or above INR 2-3. According to a recent survey, almost a quarter of physicians employ rhythm control to treat AFib, and many of these believe that rhythm control decreases stroke and mortality risk sufficiently that anticoagulation therapy is not necessary. In addition, many physicians believe that when AFib is paroxysmal as opposed to permanent, then risk of stroke is low enough that long-term anticoagulation is not necessary. As discussed in this review, however, neither of these beliefs is true. Regarding bleeding risk, the same survey found that physicians perceive the risks of anticoagulation to be far greater than the benefits. Again, the evidence reveals that the patients at highest risk of bleeding are also at highest risk of stroke, and the benefits of preventing stroke with anticoagulation therapy almost always outweigh the risk of bleeding. This is discussed in the context of the new NOACs (discussed in the next review), including addressing what physicians should do if patients move from warfarin to one of the NOACs or vice versa. A final challenge for physicians treating patients with AFib has been the often mistaken belief that patients are at a low-risk status, and this review concludes with an overview of the use of the CHADS2 versus the CHA2DS2-VASc risk scoring systems, including why CHA2DS2-VASc provides a better assessment of which patients are or are not at low risk.