Transcatheter Aortic Valve Thrombosis Despite Apixaban

BACKGROUND: Prosthetic valve thrombosis is an increasingly recognized complication following transcatheter aortic valve replacement, yet optimal anticoagulation strategies-particularly in patients with concurrent prothrombotic conditions-remain incompletely defined. CASE SUMMARY: A 78-year-old woman with prior transcatheter aortic valve replacement and baseline prosthesis-patient mismatch presented with acute pulmonary embolism and progressively elevated transvalvular gradients. Despite 5 months of apixaban therapy, her mean gradient continued to worsen. Hypercoagulable workup identified borderline-positive antiphospholipid antibodies. After transition to warfarin, mean transvalvular gradient decreased from 40 to 24 mm Hg, with marked symptomatic improvement. DISCUSSION: This case illustrates the potential inadequacy of direct oral anticoagulants for clinically significant transcatheter valve thrombosis, particularly in the presence of antiphospholipid antibodies, for which randomized data support superiority of vitamin K antagonist therapy. TAKE-HOME MESSAGE: Clinicians should consider vitamin K antagonist therapy over direct oral anticoagulants for clinically significant bioprosthetic valve thrombosis, especially when concurrent antiphospholipid antibodies are identified.