Benfluorex-induced mitral stenosis: A misknown etiology

Abstract

A 60-year-old Caucasian overweight female patient with history of three uneventful pregnancies and benfluorex intake 150 mg t.i.d. for eight years who developed progressive dyspnea over the past two years. No history of rheumatic fever was found. Cardiac auscultation revealed holosystolic murmur, opening snap and prolonged diastolic murmur. Chest X-ray revealed normal heart size, venous congestion and right pleural effusion (proteins 25 g/l). Echocardiography examination found normal ejection fraction, enlarged left atrial size, mild aortic regurgitation and mild-to-moderate mitral regurgitation with thickened and shortened leaflet and subvalvular apparatus, bicommissural fusion resulting in significant mitral stenosis (mean and maximal gradients were 16 and 28 mm Hg respectively) (Fig. 1 A,B, movie). Systolic transtricuspid gradient was 36 mm Hg. The patient underwent surgical valve replacement with a mechanical bileaflet valve. Per-operative findings were a funnel-shaped mitral apparatus, localized calcification on A3 and leaflet thickening with bicommissural fusion. The subvalvular apparatus was thickened and shortened with interchordal fusion (Fig. 1 C). Pathology examination demonstrated drug-induced valvular disease by showing non-inflammatory endocardial fibrosis that predominates on ventricular side of the valvular apparatus (Fig. 1 D). Due to vitamin K antagonist mediated excessive bleeding the patient died four years later.