Dopamine Agonists and Valvular Heart Disease

To the Editor: Schade et al. (Jan. 4 issue) 1 report an adjusted incidence-rate ratio of 4.9 for valvular regurgitation among patients taking the dopamine agonist cabergoline, especially at a daily dose above 3 mg and a duration of use of 6 months or more. The authors also report an incidence-rate ratio of 2.6 for cabergoline at a dose of 3 mg or less, adjusted for the cumulative duration of use. In the same issue, Zanettini et al. 2 report a relative risk of moderate or severe valvular regurgitation of 4.6 to 7.3 among patients taking cabergoline. They also describe a dose . . .