Risk for Valvular Heart Disease among Users of Fenfluramine and Dexfenfluramine Who Underwent Echocardiography before Use of Medication

1 December 1998 | Volume 129 Issue 11 Part 1 | Pages 870-874

Background: Because uncontrolled echocardiographic surveys suggested that up to 30% to 38% of users of fenfluramine and dexfenfluramine had valvular disease, these drugs were withdrawn from the market.

Objective: To determine the risk for new or worsening valvular abnormalities among users of fenfluramine or dexfenfluramine who underwent echocardiography 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 worsening valvulopathy, defined as progression of either aortic or mitral regurgitation by at least one degree of severity and disease that met U.S. Food 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 aortic valve and mild aortic regurgitation that progressed to moderate regurgitation. The second patient developed new moderate aortic insufficiency.

Conclusion: Users of diet medications are at risk for valvular heart disease. However, the incidence may be lower than that reported previously.

Author and Article Information

From the Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts; and University of Massachusetts Medical Center and University of Massachusetts Medical School, Worcester, Massachusetts.
Acknowledgments: The authors thank Gail Lucey, RN, for coordinating the study at the University of Massachusetts site, Minesh Patel for data collection, Andrea Sweeney-Walsh for performing sonography, and all of the physicians and patients for their participation.
Grant Support: Dr. Wee is supported by a National Research Service Award training grant (#5 T32 PE11001).
Requests for Reprints: Christina C. Wee, MD, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Libby 330, Boston, MA 02215; e-mail, cweekuo@bidmc.harvard.edu.
Current Author Addresses: Drs. Wee, Phillips, and Kriegel: Division of General Medicine, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215.
Dr. Douglas and Ms. Riley: Division of Cardiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215.
Dr. Erban: Division of General Medicine, University of Massachusetts Memorial Health Care, 55 Lake Avenue North, Room A3-139, Worcester, MA 01655.
Dr. Aurigemma: Division of Cardiology, University of Massachusetts Medical Center, S3-860, 55 Lake Avenue North, Worcester, MA 01655.