Increased prevalence of subclinical cardiac valve fibrosis in patients with prolactinomas on long-term bromocriptine and cabergoline treatment

Background: In contrast to cabergoline, evidence-based information about a possible profibrotic effect of bromocriptine in prolactinoma patients is extremely limited. Objective: To assess the prevalence of valvular lesions among patients on long-term bromocriptine or cabergoline therapy. Design: Case-control study. Methods: A transthoracic echocardiographic evaluation was performed in 334 subjects divided into four groups: 103 cabergoline treated, 55 bromocriptine treated, 74 naive patients, and 102 controls. Results: Clinically relevant valve regurgitations were equally prevalent in all investigated groups whereas subclinical valve fibrosis was significantly more frequent in both bromocriptine- and cabergoline-treated patients (40 vs 43.6 vs 21.6 vs 23.5%; P=0.004). The odds ratio (OR) for developing valvular fibrosis was 2.27 (95% CI 1.17-4.41; P=0.016) for cabergoline and 2.66 (95% CI 1.22-5.78; P=0.014) for bromocriptine groups compared with subjects not exposed to dopamine agonists (DAs). A significantly higher pulmonary arterial pressure corresponding to the longer treatment duration was observed among patients taking bromocriptine compared with cabergoline-treated subjects. Conclusions: Long-term treatment with cabergoline and bromocriptine seems not to be associated with an increased risk of clinically significant valve disease but possible subclinical lesions should be expected. An echocardiographic examination is recommended at the beginning and periodically during therapy with DAs acting as full or partial agonists of 5-hydroxytrytamine 2B receptors (cabergoline and bromocriptine). Bromocriptine seems not to be a safe alternative for patients receiving cabergoline treatment who have preexisting or diagnosed abnormalities suggesting valvular, interstitial myocardial, or pulmonary fibrosis. Further studies are needed to investigate the possible impact of DA treatment on pulmonary arterial pressure.