Low-dose apixaban in HeartMate 3 LVAD patients, interim analysis of the ApixiVAD trial, a randomized controlled study

Left ventricular assist devices (LVADs) improve outcomes in advanced heart failure but require anticoagulation. Vitamin K antagonists (VKAs) have significant limitations, with labile international normalized ratios and suboptimal time in therapeutic range (TTR), associated with increased morbidity and mortality. Direct oral anticoagulant therapy has been contraindicated in LVAD patients.

The ApixiVAD study, a 1:1 randomized, open-label pilot trial, compared the reduced-dose apixaban (2.5 mg twice daily) with standard VKAs in stable HeartMate 3 patients with TTR > 60%. Aspirin was not mandated. Primary outcomes included thromboembolic events, bleeding, and death.

Forty-four patients were randomized, 21 to apixaban and 23 to VKA. Median age was 55 years (50-64), and 6 were women (14%). The median time from LVAD implantation to randomization was 6 months (range 5-8). Patients were followed for a median of 6 months (2-8). Twenty-five (57%) were transplanted, 12 (27%) were still on treatment, and 5 (11%) had undergone a primary outcome. Event-free survival was similar between groups (hazard ratio [HR] 1.46, 95% confidence interval [CI] 0.64-3.35, p = 0.4, Cox model) as well as Blood product use at transplantation.

These interim results were obtained after the end of recruitment but before all patients reached the full follow-up duration. The rates of bleeding observed in the apixaban group were below those reported in large international studies without any increase in thrombosis, suggesting that apixaban 2.5 mg twice daily may offer an effective balance between bleeding risk and anticoagulation efficacy. These findings should be interpreted as preliminary and hypothesis-generating.