Long-term cabergoline therapy is not associated with valvular heart disease in patients with prolactinomas

Ergot-derived dopamine receptor agonists, especially pergolide and cabergoline, have been associated with an increased risk of valvular heart disease in patients treated for Parkinson's disease. Cabergoline at lower doses than those employed in Parkinson's disease is widely used in patients with prolactinomas, because of its high efficacy and tolerability; however, its safety with regard to cardiac valve disease is unknown. In order to assess the prevalence of cardiac valve regurgitation in patients with prolactinomas treated with long-term cabergoline, we performed a prospective and multicentric study including four university centers in the province of Quebec. A transthoracic echocardiogram was performed in 70 patients with prolactinomas treated with cabergoline for at least 1 year (duration of treatment, 55 +/- 22 months; cumulative dose 282 +/- 271 mg, mean +/- SD) and 70 control subjects matched for age and sex. Valvular regurgitation was graded according to the American Society of Echocardiography recommendations as mild, moderate, or severe. Moderate valvular regurgitation was found in four patients (5.7%) and five control subjects (7.1%) (P = 0.73). No patient had severe valvular regurgitation. There was no correlation between the presence of significant heart-valve regurgitation and cabergoline cumulative dose, duration of cabergoline treatment, prior use of bromocriptine, age, adenoma size, or prolactin levels. Our results show that low doses of cabergoline seem to be a safe treatment of hyperprolactinemic patients. However, in patients with prolonged cabergoline treatment, we suggest that echocardiographic surveillance may be warranted.