Acute Thrombosis of a Prosthetic Mitral Valve: A Lesson in Anticoagulation

Prosthetic heart valve thrombosis is a potentially life-threatening complication of low anticoagulation. We present a case of acute prosthetic mitral valve thrombosis in a patient whose anticoagulation was inadequate after phenindione was changed to low molecular weight heparin. We discuss the diagnosis and treatment of this condition and highlight the danger of long-term low molecular weight heparin use in patients with prosthetic heart valves, especially those in the mitral position. We review the current guidelines for anticoagulation of prosthetic heart valves and discuss potential treatment options if adequate anticoagulation is not achieved by oral anticoagulant alone.