The use of high doses of the ergot-derived dopamine receptor agonists such as cabergoline for treatment of Parkinsons disease has been associated with increased prevalence of echocardiography detected cardiac valve disease. Whether smaller doses of cabergoline used for treating endocrine disorders causes similar valvular abnormalities is not yet conclusively established.
We conducted echocardiographic screening of 35 adult endocrine patients on current treatment with cabergoline. The mean age of the participants was 42 years with a female to male ratio of 4:1. The mean cumulative dose of cabergoline used was 559 mgs. None of the patients had clinically significant (moderate to severe) valvular regurgitation. Five patients (14%) had mild to moderate regurgitation (two patients each of the aortic and mitral valves, one involving the tricuspid valve). Cumulative doses for these patients ranged between 120 and 400 mgs, except for one patient who received a high cumulative dose of 1400 mgs.
Although this study describes a relatively small patient sample, our finding of no clinically significant cardiac valve disease among cabergoline-treated patients with pituitary disease is similar to the outcome of previously conducted cross-sectional case controlled studies. However three of the six cross-sectional studies reported so far have shown an increased prevalence of mild to moderate tricuspid regurgitation, which has raised concerns. Prospective studies with sufficient power are required to investigate the true prevalence of cardiac valve disease related to the modest doses of cabergoline normally used in endocrine practice.
Recent advice from the UK Medicines and Health products Regulatory Agency (MHRA) recommends echocardiography screening for cardiac valvulopathy within 36 months of initiating cabergoline treatment and subsequently at frequent intervals. With a cohort of this size, an endocrine service would incur an additional annual cost of over £10 000 to perform echocardiographic screening twice per year. The cost-effectiveness of such screening remains to be determined.