Cabergoline therapy for prolactinomas: is valvular heart disease a real safety concern?

Dopamine agonists (DAs) are the first-line therapy for the treatment of hyperprolactinemia, with cabergoline, an ergot-derived selective D(2)-receptor agonist, being the preferred and most widely used drug. Recent studies reported cardiac valve regurgitations in patients with Parkinson's disease treated with high doses of DA, raising concerns about the safety of cabergoline in patients with hyperprolactinemia. To date, seven case-control studies have examined the potential association between cardiac valvular abnormalities and cabergoline therapy in patients with hyperprolactinemia. Overall, a total of 463 patients exposed to low doses of cabergoline (mean cumulative doses: 204-443 mg) for a mean duration of 45-79 months have been included in these studies. Patients in all the studies were asymptomatic without clinical signs of cardiac disease. Six studies did not show any association between cabergoline therapy and clinically relevant valvular regurgitation, whereas one study found an increased rate of moderate tricuspid regurgitation. In this report, we review and discuss the results of these studies and emphasize the limitations of the methodology used in the published literature. The clinical significance of the present findings has yet to be confirmed by future larger prospective studies with rigorous echocardiographic protocols and prolonged duration of follow-up.