Fen-Phen e-Resource

Dr. Bruce K. Shively from Oregon Health Sciences University, in Portland, and a multicenter group obtained echocardiograms for 172 matched pairs of dexfenfluramine users and controls, as well as 51 unmatched patients and 17 controls, to study the prevalence and severity of valve disease.

Patients had taken dexfenfluramine for an average of 7 months, and the time between their last dose and their echocardiogram averaged 8.5 months, the investigators report.

While no moderate (3+) or severe (4+) aortic regurgitation was found among the patients or controls, mild (2+) aortic regurgitation was found significantly more often among dexfenfluramine patients (6.3%) than among controls (1.6%), the investigators report. "[N]o significant differences were seen between the dexfenfluramine and control groups in the prevalence of FDA-grade mitral regurgitation, each individual grade of mitral regurgitation, or the presence of any mitral regurgitation," the authors write.

Dexfenfluramine patients and controls did not differ in the frequencies of valvular sclerosis or valve mobility, the report indicates. "Duration of dexfenfluramine treatment was not related to valve regurgitation in the present study," the researchers indicate, but "[t]he prevalence of any degree of aortic regurgitation was significantly higher [at 30.3%] in dexfenfluramine patients with an interval from drug discontinuation to echocardiogram of less than 8 months," versus 15.7% for an interval of 8 months or more.

"The hypothesis that the use of dexfenfluramine is associated with potentially clinically significant valve regurgitation is supported by the present study," the authors conclude. "Furthermore, the decline in the frequency of regurgitation over time after drug discontinuation may indicate the potential for regression of valvulopathy associated with dexfenfluramine."