Incidence of Cabergoline-Associated Valvulopathy in Primary Care Patients With Prolactinoma Using Hard Cardiac Endpoints

Background Controversy exists as to whether low-dose cabergoline is associated with clinically significant valvulopathy. Few studies examine hard cardiac endpoint data, most relying on echocardiographic findings. Objectives To determine the prevalence of valve surgery or heart failure in patients taking cabergoline for prolactinoma against a matched nonexposed population. Design Population-based cohort study based on North East London primary care records. Methods Data were drawn from similar to 1.5 million patients' primary care records. We identified 646 patients taking cabergoline for >6 months for prolactinoma. These were matched to up to 5 control individuals matched for age, gender, ethnicity, location, diabetes, hypertension, ischemic heart disease, and smoking status. Cumulative doses/durations of treatment were calculated. Cardiac endpoints were defined as cardiac valve surgery or heart failure diagnosis (either diagnostic code or prescription code for associated medications). Results A total of 18 (2.8%) cabergoline-treated patients and 62 (2.33%) controls reached a cardiac endpoint. Median cumulative cabergoline dose was 56 mg (interquartile range [IQR] 27-123). Median treatment duration was 27 months (IQR 15-46). Median weekly dose was 2.1 mg. Neither univariate nor multivariate analysis demonstrated a significant association between cabergoline treatment at any cumulative dosage/duration and an increased incidence of cardiac endpoints. In a matched analysis, the relative risk for cardiac complications in the cabergoline-treated group was 0.78 (95% CI, 0.41-1.48; P = 0.446). Reanalysis of echocardiograms for 6/18 affected cabergoline-treated patients showed no evidence of ergot-derived drug valvulopathy. Conclusions The data did not support an association between clinically significant valvulopathy and low-dose cabergoline treatment and provide further evidence for a reduction in frequency of surveillance echocardiography.