Direct oral anticoagulants and warfarin safety in rural patients with obesity

are at an increased risk for atrial fibrillation, an irregular heart rhythm that can lead to cardioembolic stroke. Guideline directed medical therapy for the prevention of thromboembolic (TE) events such as stroke in patients with atrial fibrillation or flutter remains anticoagulation. Warfarin remains one of the most widely prescribed anticoagulants for patients with atrial fibrillation but comes with a number of challenges including the need for regular international normalized ratio (INR) testing to ensure levels fall within the therapeutic range. Direct oral anticoagulants (DOACs), such as the factor Xa inhibitors (i.e. apixaban and rivaroxaban), are relatively new medications that have become attractive alternatives to warfarin as they have fewer monitoring and follow-up requirements, a more rapid on-set and off-set, and fewer medication and dietary interactions. Despite these advantages, data on factor Xa inhibitors’ efficacy and safety in individuals with atrial fibrillation and concurrent obesity are limited and in some cases, such as in patients with class III obesity (BMI greater than 40kg/m ² ), guidelines advise against their use. Despite this limitation, studies evaluating warfarin in individuals with obesity have illustrated it can be used safely and effectively although higher doses and additional monitoring may be required. ^, For the DOACs, only half of the large phase 3 approval studies investigated the medications’ safety and efficacy by weight categories. In a review of available studies, it was determined that data were of insufficient quality while evidence of venous TE event prevention was lacking compared to stroke prevention in the subgroup of patients with Class 3 obesity treated with DOAC therapy. Finally, DOAC medication use has been found to be lower amongst rural Medicare beneficiaries compared to their urban counterparts. While the described advantages of DOACs warrant their use in all areas of the country, rural areas are most commonly associated with higher rates of obesity,

which could at least partially explain hesitancy on their use in these regions.

Given the current, growing incidence of atrial fibrillation and trends in obesity for the US, more studies are needed to verify the efficacy and safety of DOAC medications compared to warfarin and particularly in rural populations.

^, The current study was designed to evaluate the question: In atrial fibrillation patients with concurrent class III obesity, is DOAC anticoagulation, specifically apixaban and rivaroxaban, as effective and safe in terms of TE and bleeding events, respectively, as warfarin anticoagulation during the first 6-12 months of therapy in a rural community?