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

Abstract

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 ~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.