Category: Federal Forum Posters
Purpose: Current guidance from the International Society on Thrombosis and Haemostasis suggests using standard dosing of direct oral anticoagulants (DOACs) in most obese patients, but switching to warfarin in patients of extreme body weight (e.g., weight over 120 kg or BMI over 40 kg/m2). However, clinical outcomes data is still lacking, particularly for extremely obese individuals treated with DOACs and obese patients treated with warfarin. The objective of this study is to determine whether weight and body mass index (BMI) are associated with differences in effectiveness and safety in patients with atrial fibrillation treated with warfarin or a DOAC.
Methods: A retrospective chart review will be conducted including patients at the Veteran Affairs Boston Healthcare System initiated on warfarin or a DOAC (dabigatran, rivaroxaban, apixaban, edoxaban) for stroke prevention in atrial fibrillation between October 1, 2010 and December 31, 2018. Veterans will be excluded if they are underweight (weight below 60 kg or BMI below 18.5 kg/m2) or have been on therapy for under one year. Demographic data will include: age, sex, weight, BMI, blood pressure, type of atrial fibrillation, CHA2DS2-VASc, serum creatinine, and anticoagulant and will be collected at initiation and time of event. Veterans will be categorized by weight and BMI into the following: normal (weight 60 to 74.9 kg or BMI 18.5 to 24.9 kg/m2), overweight (weight 75 to 89.9 kg or BMI 25 to 29.9 kg/m2), obese (weight 90 to 120 kg or BMI 30 to 40 kg/m2), or morbidly obese (weight over 120 kg or BMI over 40 kg/m2). The primary outcome measure will be a composite of ischemic stroke or systemic embolism. Secondary outcomes include incidence of major and clinically relevant non-major bleeding. Adherence to therapy will be accounted for using time in therapeutic range for warfarin and proportion of days covered for DOACs.
Results: not applicable
Conclusion: not applicable
Yemen Yang– PGY1 Pharmacy Resident, VA Boston Healthcare System, Boston, MA