Valvular abnormalities and cardiovascular status following exposure to dexfenfluramine or phentermine/fenfluramine.
BACKGROUND
Fenfluramine and dexfenfluramine were voluntarily withdrawn from the market in September 1997 because of reports of an association with heart valve abnormalities. Studies have been limited by lack of comparison with untreated controls.


OBJECTIVE
To evaluate cardiovascular status and the prevalence of valvular abnormalities, as assessed by clinical cardiovascular parameters and echocardiography, in patients treated for obesity with dexfenfluramine or phentermine/fenfluramine.


METHODS
Reader-blinded controlled study completed in February 1998.


METHODS
Twenty-five clinical centers in the United States. Of 1640 enrolled subjects, 1473 were eligible (479 and 455 had taken dexfenfluramine and phentermine/fenfluramine, respectively, continuously for 30 days or more in the previous 14 months, and 539 were untreated matched controls) and provided clinical and echocardiographic data. Mean (SD) age was 47.4 (11.4) years, mean body mass index was 35.0 (7.4) kg/m2, and 74% were women. Mean (SD) duration of therapy was 6.0 (3.3) months (range, 1-18.4 months) in the dexfenfluramine group, and 11.9 (10.4) months (range, 1.4-63 months) in the phentermine/fenfluramine group, while the untreated group had no anorexigen use during the previous 5 years.


METHODS
Cardiovascular signs and symptoms; echocardiographic evidence of aortic (AR) or mitral (MR) regurgitation according to US Food and Drug Administration (FDA) criteria (AR > or = mild or MR > or = moderate) and by grade; tricuspid and pulmonic valve regurgitation; and aortic, mitral, and tricuspid valve leaflet mobility and thickness, for treated vs untreated subjects.


RESULTS
Cardiovascular signs and symptoms were similar among anorexigen-treated and untreated subjects. Prevalence rates and relative risk (RR) of AR were significantly increased in anorexigen-treated patients and were 8.9% in the dexfenfluramine group (RR, 2.18; 95% confidence interval [CI], 1.32-3.59), 13.7% in the phentermine/fenfluramine group (RR, 3.34; 95% CI, 2.09-5.35), and 4.1% in the untreated group (P<.001). No statistically significant differences in prevalence were observed for MR, thickening or decreased mobility of any valve leaflet, calculated pulmonary artery systolic pressure, or left ventricular ejection fraction. Serious cardiac events (including myocardial infarction, congestive heart failure, or ventricular arrhythmia) occurring at any time were not statistically different in treated and untreated subjects (dexfenfluramine, 9.0%; phentermine/fenfluramine, 4.0%; and untreated, 8.4%); and following anorexigen treatment were uncommon (dexfenfluramine, 2.3%; phentermine/fenfluramine, 2.4%, and untreated, 3.3%, when adjusted for the median start date of anorexigen use).


CONCLUSIONS
Our data indicate that use of dexfenfluramine and phentermine/fenfluramine is associated with an increase in the prevalence of AR using FDA echocardiographic criteria, but was not associated with an increase in the prevalence of MR using FDA criteria or with serious cardiac events.
Gardin
J M
JM
Division of Cardiology, University of California, Irvine, USA.
Schumacher
D
D
Constantine
G
G
Davis
K D
KD
Leung
C
C
Reid
C L
CL
D001022:Aortic Valve Insufficiency / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000453:epidemiology; D001067:Appetite Depressants / Q000009:adverse effects*; D015992:Body Mass Index; D020372:Dexfenfluramine / Q000009:adverse effects*; D015150:Echocardiography, Doppler; D005260:Female; D005277:Fenfluramine / Q000009:adverse effects*; D006349:Heart Valve Diseases / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000453:epidemiology; D006351:Heart Valves / Q000000981:diagnostic imaging; D006801:Humans; D016015:Logistic Models; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000453:epidemiology; D009765:Obesity / Q000188:drug therapy; D010645:Phentermine / Q000009:adverse effects*; D015995:Prevalence; D012306:Risk; D018490:Serotonin Agents / Q000009:adverse effects*; D018709:Statistics, Nonparametric
D001067:Appetite Depressants; D018490:Serotonin Agents; D005277:Fenfluramine; D010645:Phentermine; D020372:Dexfenfluramine