Mitral valve replacement in idiopathic eosinophilic endocarditis without peripheral eosinophilia

Idiopathic hypereosinophilic syndrome (IHS) is a rare systemic disease than can cause multiple organ failure by eosinophilic infiltration. Cardiac involvement is characterized by endocardial fibrosis and overlying thrombus leading to restrictive cardiomyopathy and valvular dysfunction. The absence of peripheral eosinophilia does not exclude eosinophilic cardiac involvement. Surgical experience of patients with mitral dysfunction caused by this syndrome is limited and valvular replacement is most often performed. Mechanical valvular replacement has a high incidence of recurrent obstructive thrombosis and replacement by bioprosthesis is recommended despite associated restrictive cardiomyopathy. This report describes a patient who presented mitral insufficiency caused by eosinophilic endocarditis without peripheral eosinophilia who underwent mitral valve replacement.