Recurrent ischaemic strokes as a first presentation of Libman-Sacks endocarditis with an atypically massive mitral vegetation resulting in severe valvular regurgitation: a case report.

Background: Libman-Sacks endocarditis is a form of non-bacterial thrombotic endocarditis, associated with autoimmune conditions such as systemic lupus erythematosus and antiphospholipid syndrome (APLS). Vegetations are usually small and are managed with immunosuppression and anticoagulation. Case summary: A 50-year-old female presented to her hospital with left leg weakness, with imaging showing a right parietal stroke and an old occipital lobe stroke. Inpatient transthoracic echocardiography showed a large mitral valve (MV) vegetation with moderate-to-severe mitral regurgitation (MR). She self-discharged against medical advice before further workup could be completed and was lost to follow-up until persuaded to have an outpatient transoesophageal echocardiogram, which showed severe MR with a large (2 cm × 3 cm) mass attached to the posterior MV leaflet. Blood cultures were negative. Review of previous blood tests showed a triple-positive APLS panel, which was positive on repeat testing. She underwent successful mechanical MV replacement. Valve histology was consistent with Libman-Sacks endocarditis. Warfarin therapy was continued, complicated by subdural haematoma (successfully treated), but with no further thrombo-embolic events. Subsequent anti-nuclear antigen testing was positive, and hydroxychloroquine was commenced. Transoesophageal echocardiography 1 year later showed a well-functioning MV prosthesis. Discussion: The management of young individuals with ischaemic stroke should include attention to atypical causes. Libman-Sacks endocarditis is usually associated with small vegetations and high thrombotic risk, usually managed medically with anticoagulation and treatment of underlying conditions. Our case was atypical, with the presence of a large vegetation causing significant valvular dysfunction, but it demonstrates that replacement with mechanical prostheses can be a feasible management strategy.