Evaluation of the efficacy of direct oral anticoagulants (DOACs) in comparison to warfarin in morbidly obese patients

ABSTRACT Purpose: There is limited clinical data evaluating anticoagulation with the direct oral anticoagulants (DOACs) in morbidly obese patients. We sought to examine the efficacy in preventing stroke or other systemic embolic events and safety of apixaban, dabigatran, and rivaroxaban, in comparison to warfarin in patients with either a body-mass index (BMI) over 40 kg/m2 and/or a weight over 120 kg. Methods: After approval from IRB, we collected retrospective data from our institution’s records on 180 patients. We analyzed the rates of stroke and systemic embolic events as defined as ischemic stroke, pulmonary embolism (PE), deep vein thrombosis (DVT), and myocardial infarction (MI) as well as major bleeding in morbidly obese patients receiving apixaban, dabigatran, or rivaroxaban in comparison to warfarin for anticoagulation due to nonvalvular atrial fibrillation, postoperative thrombus prophylaxis, or DVT/PE treatment and/or reduction in risk for recurrence. Results: The final analysis included 90 patients in both arms. Fifty-two percent (n = 41) of patients in the DOAC group were on apixaban therapy, 12% (n = 11) on dabigatran, and 37% (n = 33) on rivaroxaban. The average BMI and weight in the DOAC group were 46.7 kg/m2 and 139.3 kg, respectively. In the warfarin group, average BMI and weight were 45.8 kg/m2 and 135.9 kg, respectively. There were 11 patients who developed a stroke or thromboembolic event in the DOAC group and 10 in the warfarin group (OR 1.11, 95% confidence interval [CI] 0.45–2.78; p = 0.82). The events in the DOAC group consisted of three patients who developed ischemic stroke, three patients who developed DVTs, one who developed a PE, and four patients who developed MIs. There were two major bleeding events in the DOAC group and three events in the warfarin group (p = 0.65). Conclusions: Anticoagulation therapy with DOACs in morbidly obese patients may be a safe and effective alternative to warfarin for prevention of stroke or systemic embolic events. However, additional studies are necessary to confirm these findings.