Mitral bioprosthesis hypertrophic scaring and native aortic valve fibrosis during benfluorex therapy.

The authors describe the case of a simultaneous mitral bioprosthesis hypertrophic scaring and native aortic valve fibrosis during benfluorex therapy in a 40-year-old woman. Four years before, she underwent a mitral valve replacement after the diagnosis of mitral regurgitation during benfluorex treatment (150 mg/day). This drug was reintroduced postoperatively. She presented with exercise and sometimes resting dyspnoea. The bioprosthesis and aortic valves exhibited similar histopathological lesions. Thickening and plaque deposits made by smooth muscle alpha actin- and vimentin-positive cells in a glycosaminoglycan matrix were observed. The study discusses the putative contribution of circulating progenitor cells activated by 5-HT(2B) receptor agonists in the development of drug-induced heart disease.