Endocrine Abstracts

Background: Cabergoline-associated valvulopathy (CAV) is an established complication of cabergoline therapy in Parkinson’s disease, with a definitive echocardiographic triad of severe regurgitation, leaflet thickening, and restricted valve movement without calcification. Long-term cabergoline therapy is deemed safe for prolactinoma due to low dosage. We describe the first UK case report of aortic regurgitation (AR) associated with low-dose cabergoline in prolactinoma.

Case Report: A 67-year-old male with no significant past medical or drug history presented with constipation. Initial investigations demonstrated a T4 of 6.5 pmol/l (normal range, nr, 7–17 pmol/l), and subsequently a prolactin of 79 000 uIu/ml (nr 60–315 uIu/ml). Magnetic resonance imaging of the pituitary revealed a 3.5×2.4×2.5 cm macroadenoma. He was commenced on Cabergoline, initially 1 mg twice weekly but increasing over two months to 2 mg twice weekly. At three months a baseline echocardiogram highlighted mild mitral regurgitation and AR, with aortic valve peak gradient 6.86 mmHg and normal left ventricular (LV) function. His prolactinoma responded well to cabergoline and his dose was reduced to 1.5 mg twice weekly. Three years later he reported mild exertional dyspnoea; his cumulative cabergoline dose was 496 mg. Echocardiogram demonstrated moderate AR. Repeat echocardiogram at six months (cumulative dose 574 mg) showed severe AR with characteristically thickened leaflets and the absence of calcification. Ejection fraction was preserved (65–70%) with normal LV function. Cabergoline was stopped and quinagolide commenced. Two subsequent echocardiograms showed stabilisation of AR without progression of symptoms.

Discussion: The echocardiographic signs and rapid disease progression confirm this case report as only the second demonstrating AR-type CAV in prolactinoma. Notably, AR occurred at a low cumulative cabergoline dose. Given recent Society for Endocrinology guidelines, we emphasise the importance of echocardiogram screening for patients commencing cabergoline for prolactinoma, and thorough assessment for symptoms of CAV at follow-up prior to the recommended five-year repeat echocardiogram.