Bromocriptine use and the risk of valvular heart disease

It has been reported that patients on pergolide and carbergoline have an increased risk of developing valvular heart disease. It is uncertain if bromocriptine, an ergot-derived dopamine agonist (DA) with partial 5-HT(2B) activity, is associated with a similar risk. We assessed the frequency of valvular heart disease in Parkinson's disease (PD) patients on bromocriptine compared to pergolide and a control group of PD patients who had not been treated on any DA. Seventy-two PD patients on bromocriptine, 21 patients on pergolide, and 47 control PD patients were recruited. Transthoracic echocardiographic studies were performed and reviewed by a blinded cardiologist. The risk for the bromocriptine group to develop any abnormal valvular regurgitation was 3.32 (adjusted OR, 95% CI: 1.11-9.92, P = 0.03) compared to controls, whereas the risk for the pergolide group was 3.66 (adjusted OR, 95% CI: 1.22-10.97, P = 0.02). When cumulative dose of bromocriptine was analyzed by quartiles, patients with a greater exposure to bromocriptine had significantly higher risk of developing both mild and moderate-severe regurgitations (P for trend, 0.005 and 0.019, respectively). This study demonstrated that bromocriptine use was associated with an increased risk of developing valvular heart disease, which occurred in a cumulative dose-dependent manner.