In the U.S. about 2.7 to 6.1 million people have atrial fibrillation (AF). 1 This condition affects the rhythm of the heart, causes blood in the heart to become stagnant, and puts patients at high risk for developing a systemic embolism, particularly a stroke.1 Recent studies have shown that AF accounts for at least 15% of all strokes in the U.S. and 36% of strokes in people aged > 80 years. 2
For patients aged > 60 years, the gold standard of long-term anticoagulation for reducing the risk of stroke has been oral vitamin K antagonist (warfarin) therapy. 2 Although overwhelming evidence exists that supports the use of warfarin in these patients, warfarin is a narrow therapeutic index medication that requires frequent laboratory monitoring of international normalized ratio (INR) for dose titration guidance. There is also strong evidence that pharmacist-run anticoagulation clinics have improved patient-centered outcomes in patients prescribed warfarin. 3-5
Direct oral anticoagulants (DOACs) are recently approved oral medications used as alternatives to warfarin for anticoagulation in AF. Direct oral anticoagulants do not require INR monitoring or any laboratory test for efficacy. In 2010, the FDA approved the first DOAC, dabigatran, for use in patients with AF. In 2011, rivaroxaban received approval for the same indication. One potential drawback of these new agents relative to warfarin is the lack of availability of a reversal agent that can be used in the event of a life-threatening bleeding event. Dabigatran is the only DOAC with an FDA-approved available reversal agent. In both 2011 and 2012, dabigatran, warfarin, and other anticoagulants topped the Institute for Safe Medicine Practice list of suspect drugs related to adverse events (AEs). These data prompted the Joint Commission to incorporate anticoagulation into the 2017 National Hospital Patient Safety Goals to improve patient outcomes and reduce harm from use of anticoagulants. 6
In early 2011, the VHA produced national guidance on the treatment of patients who receive DOACs; this guidance was updated most recently in September 2016. 7 Patients who were receiving DOACs at the Ralph H. Johnson VAMC (RHJVAMC) were initially monitored by 12 primary care pharmacists at the main hospital or at community-based outpatient clinics (CBOCs). Ambulatory care pharmacists at RHJVAMC work under a scope of practice to prescribe and adjust certain classes of medications to provide the highest level of care to more than 65,000 veterans in South Carolina and Georgia. Historically at RHJVAMC, warfarin has been the anticoagulant most commonly used for AF, though dabigatran and rivaroxaban have gained in popularity after being added to the national VA formulary.
In November 2012, for better monitoring of patient outcomes, improved efficiency of the primary care pharmacist clinics, and increased access to care in these clinics, treatment of patients prescribed DOACs was shifted to a centralized model that involved 3 anticoagulation clinical pharmacy specialists.
Centralized pharmacy services have a small number of core team members in a specific service for a particular disease, which reduces the number of different pharmacists a patient could talk to for management of a particular condition. Centralized pharmacy services allow for streamlining anticoagulation management to a small group of individual pharmacists considered specialists in anticoagulation. This shift in management to centralized anticoagulation services was supported at RHJVAMC by findings from a study of a pharmacist-run centralized anticoagulation clinic: Patients treated by the centralized clinic were 39% less likely to experience an anticoagulation therapy complication. 8