Cardiac Valve Complications in Prolactinomas Treated With Cabergoline

Dopamine agonists are first-line agents for the treatment of prolactinomas (1) and Parkinson's disease (2). There is evidence supporting a causal relationship between the occurrence of drug-induced "restrictive" valvular heart disease and treatment with pergolide (3): in several cases, the valvulopathy improved when pergolide was discontinued (4). Valvular heart damage has also been reported with the ergot-derived dopamine agonists bromocriptine and cabergoline (5,6). Two recent studies (7,8) have further demonstrated that both pergolide and cabergoline are associated with an increased risk of new cardiac valve regurgitation in patients treated for Parkinson's disease. The valvular abnormalities seen with ergot-derived dopamine agonists are similar to those observed in patients receiving ergot alkaloid agents (such as ergotamine and methysergide) in the treatment of migraine, or fenfluramine and dexfenfluramine in the treatment of obesity. These abnormalities also closely resemble carcinoid-related valvulopathies (9). Cardiac valve disease has never been reported in patients with prolactinomas who require treatment with dopamine-agonists even life-long (1). At variance with patients with Parkinson's disease, patients with prolactinomas are younger and are treated with an average dose of dopamine-agonists that is significantly lower (median bromocriptine dose 5 mg/day and median cabergoline dose 1 mg/week). Because of the young age of treatment beginning (most patients with microprolactinomas start dopamine-agonist treatment in early adulthood), treatment might be continued for over 3 decades: the cumulative risk of low doses of dopamine agonists for such a long period of treatment is currently unknown. To assess the prevalence of cardiac valve disease in patients treated with cabergoline, we wish to perform an echocardiography screening in a large representative sample of patients with prolactinoma who were treated with cabergoline for at least 12 months and in