Thrombosis of mitral valve prosthesis presenting as abdominal pain

A 67-year-old woman presented with abdominal pain, anemia, and leukocytosis. Five years previously, the patient had undergone mitral valve replacement with a St. Jude bileaflet mechanical prosthesis. After her admission, echocardiography confirmed an immobile leaflet of the prosthetic valve. At urgent surgery, thrombosis and pannus, obstructing the disc, were found, and the mechanical valve was replaced with a bioprosthesis. The incidence of mitral valve thrombosis is low, ranging from 0.1% to 5.7% per patient per year. Patients who receive inadequate anticoagulation, particularly with valve prostheses in the mitral position, have an increased risk for thrombus or pannus formation. Presentation varies, from symptoms of congestive heart failure or systemic embolization, to fever or no symptoms. New or worsening symptoms in a patient with a prosthetic heart valve should raise concerns about prosthetic dysfunction. Aggressive investigation and, if indicated, urgent or emergency surgery for treatment can be lifesaving.