Use of an On-X Prosthetic Valve In A 42-Year Old Female With Antiphospholipid Syndrome.

Antiphospholipid syndrome is a rare autoimmune disease with a hypercoagulable state causing vascular thrombosis. We present the case of a 42-year old female who underwent mitral valve replacement with a mechanical valve 15 months ago. The postoperative course was uneventful, and echocardiography performed 14 months postoperatively showed good valve function. The patient developed sudden dyspnea 15 months postoperatively and was referred to our hospital. Echocardiography revealed mitral stenosis with stuck leaflets. Emergent re-mitral valve replacement was successfully performed using an On-X valve (On-X Life Technologies, Austin, TX, USA). The patient tested positive for antiphospholipid antibodies. Antiphospholipid syndrome should be considered when valve dysfunction occurs suddenly in relatively young female patients. The On-X valve may be considered as a therapeutic option in patients with antiphospholipid syndrome because of its low anticoagulation intensity.