Evaluation of the hemocompatibility of the Direct Oral Anti-Coagulant apixaban in Left Ventricular Assist Devices (DOAC LVAD) Study

Background Patients on left ventricular assist device (LVAD) support require chronic anticoagulation to reduce the risk of thromboembolic complications. Apixaban is a direct oral anticoagulant which has become first-line therapy; however, its safety in LVAD patients has not been well-described. Objectives In patients with a fully magnetically levitated LVAD, treatment with apixaban will be feasible and comparable with respect to safety and freedom from the primary composite outcome of death or major hemocompatibility-related adverse events (HRAE: stroke, device thrombosis, major bleeding, aortic root thrombus, and arterial non-CNS thromboembolism) as compared to treatment with warfarin. Methods The evaluation of the hemocompatibility of the Direct Oral Anti-Coagulant apixaban in Left Ventricular Assist Devices (DOAC LVAD) trial is a Phase 2, open-label trial of LVAD patients randomized 1:1 to either apixaban twice daily or warfarin therapy. All patients were required to take low-dose aspirin. Patients were followed for 24 weeks to evaluate the primary composite outcome. Results 30 patients were randomized: 14 to warfarin and 16 to apixaban. Median patient age 60 years (IQR:52,71) and 47% were Black patients. The median time from LVAD implant to randomization was 115 days (IQR:56,859). At 24-weeks, the primary composite outcome occurred in no patients receiving apixaban and 2 patients (14%) receiving warfarin (p=0.12); these 2 patients experienced major bleeding from gastrointestinal sources. Conclusion Anticoagulation with apixaban was feasible in patients with an LVAD without an excess of HRAE or deaths. This study informs future pivotal clinical trials evaluating the safety and efficacy of apixaban in LVAD patients.