Endocrine Abstracts

Bromocriptine (BC) and cabergoline (CAB) are ergot-derived dopamine agonists (DAs) used for the treatment of hyperprolactinaemia. Recently, concern has been raised about a possible association between long-term DA use and cardiac valvular abnormalities. These concerns are largely derived from studies in patients with Parkinson’s disease receiving higher doses (typically CAB 3 mg/day vs 0.5–1 mg/week for hyperprolactinaemic patients). Studies in hyperprolactinaemic patients are generally reassuring but limited by their small size. We report the preliminary results of a UK-wide cross-sectional survey of echocardiographic findings in patients treated with BC/CAB for hyperprolactinaemia. The project was supported by the Clinical Endocrinology Trust and an unrestricted grant from Pfizer, UK. IRB permission was obtained at each centre. Anonymised data from 520 patients (163 male, median age 43, range 16–89) in 17 centres were collected. Studies were performed to British Society of Echocardiography standards. Patients were divided into two groups: completely normal (n=192); and those with any valvular abnormality of any severity (leaflet thickening, regurgitation, stenosis, reduced mobility or calcification, n=328). The two groups were then subdivided into BC- and CAB-treated. A two-tailed unpaired t-test was performed on the CAB-treated normal vs CAB-treated abnormal echocardiogram groups; and on the BC-treated normal vs BC-treated abnormal echocardiogram groups. There were no ‘severe’ and seven ‘moderate’ valve defects (two aortic valve thickening; two tricuspid regurgitation; one reduced aortic valve mobility; one aortic stenosis; one aortic regurgitation). Each patient’s cumulative exposure to DA was calculated. There was no statistically significant difference in the cumulative dosage of either BC (P=0.48) or CAB (P=0.13) between those with normal vs abnormal echocardiograms. There was a trend towards a higher cumulative dose of DA in the groups with normal echocardiograms. This cross-sectional survey finds no evidence of an increased prevalence of valvulopathy in patients being treated with BC or CAB for hyperprolactinaemia.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details are unavailable.