This study is being done to learn the safety and efficacy of a new anticoagulant therapy with apixaban as compared to warfarin to prevent thrombotic events while protecting from bleeding complications in patients with advanced heart failure who are chronically supported by a HeartMate 3 Left Ventricular Assist Device for 3 months.

Heart failure is a global epidemic, and Left Ventricular Assist Devices (LVADs) - particularly the HeartMate 3 (HM3) - are increasingly used due to their survival benefit over medical therapy. Despite advances, hemocompatibility-related adverse events (HRAEs) like thrombosis and bleeding remain significant causes of morbidity and mortality.

Direct Oral Anticoagulants (DOACs) have shown superiority over warfarin in heart failure patients, with lower rates of embolic and intracranial bleeding. Reduced-dose DOACs also appear to reduce major bleeding without increasing thrombotic risk. However, data on their use in LVAD patients is limited, consisting mainly of case reports, small series, retrospective analyses, and a few small randomized clinical trials.

Some reports suggest apixaban may reduce bleeding in high-risk LVAD patients, though cases of pump thrombosis and stroke have occurred. Early studies comparing DOACs to warfarin in patients with HeartMate II (HMII), HeartWare™ HVAD™ System, and The Abbott HeartMate 3 (HM3) show no significant differences in outcomes, with a trend toward less bleeding with apixaban. Two small randomized clinical trials in HM3 patients (The DOAC LVAD Study and The DOT-HM3 Study) found similar results.

This prospective, randomized, controlled, non-inferiority trial will evaluate the safety and efficacy of apixaban versus vitamin K antagonists in HM3 patients more than 3 months post-implant.

Inclusion Criteria:

• Participants will have HeartMate3 LVAD implanted > 3 months before enrollment
• ≥ 18 years old
• Treated with WARFARIN SODIUM
• Participant must provide written informed consent prior to any clinical investigation related procedure
• In female participants of childbearing capability, not currently pregnant and on appropriate contraception

Exclusion Criteria:

• Participation in any other clinical investigation(s) involving a Mechanical Circulatory Support (MCS) device, or interventional investigation(s) likely to confound study results or affect study outcome
• Presence of other anatomic or comorbid conditions, or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements, or impact the scientific soundness of the clinical investigation results
• Known allergy to Apixaban
• Bridge to transplant
• Severe renal dysfunction Estimated Glomerular Filtration Rate (eGFR) <20
• History of major bleeding event with subsequent reduction of INR goal to < 1.8
• Apixaban dose reduction criteria (Age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL)
• Aortic root thrombus