Risk for valvular heart disease among users of fenfluramine and dexfenfluramine who underwent echocardiography before use of medication

Background: Because uncontrolled echocardiographic surveys suggested that u p to 30% to 38% of users of fenfluramine and dexfenfluramine had valvular d isease, these drugs were withdrawn from the market. Objective: To determine the risk for new or worsening valvular abnormalitie s among users of fenfluramine or dexfenfluramine who underwent echocardiogr aphy before they began to take these medications. Design: Cohort study. Setting: Academic primary care practices. Patients: 46 patients who used fenfluramine or dexfenfluramine for 14 days or more and had echocardiograms obtained before therapy. Measurements: Follow-up echocardiography. The primary outcome was new or wo rsening valvulopathy, defined as progression of either aortic or mitral reg urgitation by at least one deg ree of severity and disease that met U.S. Fo od and Drug Administration criteria (at least mild aortic regurgitation or moderate mitral regurgitation). Results: Two patients (4.3% [95% CI, 0.6% to 14.8%]) receiving fenfluramine -phentermine developed valvular heart disease. One had baseline bicuspid ao rtic valve and mild aortic regurgitation that progressed to moderate regurg itation. The second patient developed new moderate aortic insufficiency. Conclusion: Users of diet medications are at risk for valvular heart diseas e. However, the incidence may be lower than that reported previously.