Effects of body mass index on the safety and effectiveness of direct oral anticoagulants: a retrospective review

Background The International Society on Thrombosis and Haemostasis recommends avoiding the use of direct oral anticoagulants (DOACs) in patients with a body mass index (BMI) greater than 40 kg/m(2) or weight greater than 120 kg. Hypothesis Higher BMI is associated with altered pharmacokinetics which may affect the safety and effectiveness for DOACs. Methods Data were collected on 3458 patients taking a DOAC prior to admission to a Midwestern health system between February 2013 and August 2016. Of these, 43 patients had a thrombotic event and 70 patients had an overt bleeding event. Patients were stratified among the following three BMI groups: BMI < 30 kg/m(2), BMI 30-40 kg/m(2), and BMI > 40 kg/m(2). Results There was no statistically significant difference between BMI groups for thrombotic events (p = 0.598) or for overt bleeding events (p = 0.065). The BMI < 30 kg/m(2) had the highest occurrence rate of bleeding events. It was observed that bleeding occurrence decreased as the BMI groups increased. The BMI > 40 kg/m(2) group had the lowest risk of bleeding events, and was the only group to have a higher occurrence rate of thrombotic events compared to bleeding events. Conclusions Among patients admitted to a single health system on DOAC therapy over a three-and-a-half-year period, obesity did not significantly correlate with thrombotic or overt bleeding complications. This study is limited as a single health system study with low overall event rates. A preliminary finding of this study showed a trend towards decreased bleeding frequency as BMI increased.