Incidence of heart valve disease in women treated with the ergot-derived dopamine agonist bromocriptine

Background: Ergot-derived dopamine agonists are thought to induce fibrotic changes in cardiac valve leaflets. We sought to determine the incidence of heart valve disease in women treated with bromocriptine compared with age and sex matched controls from the background population. Methods: In nationwide Danish registries we identified female patients treated with bromocriptine in the period 1995–2018. Patients were included at date of second redeemed prescription and were matched 1:5 with controls from the background population based on age, sex and year of inclusion by use of incidence density sampling. The outcomes were hospital admission for or outpatient diagnosis of heart valve disease, and death as competing risk. Incidence rates, cumulative incidence curves, and adjusted cox-proportional hazard models adjusted for cardiovascular risk factors were used to assess outcomes in bromocriptine users versus controls. Results: A total of 3035 female bromocriptine users and 15,175 matched controls were included. Median age at inclusion was 32 years (Q1–Q3, 28–37 years). Both bromocriptine users and controls had few comorbidities and low use of concomitant pharmacotherapy. Within 10 years of follow-up, 11 patients (0.34%, 95% CI 0.13–0.55%) and 44 controls (0.29%, 95% CI 0.20–0.37) met the primary endpoint of heart valve disease, p = 0.63. The adjusted cox regression analysis yielded a hazard ratio of 0.96 (95% confidence interval (CI) 0.55–1.69, p = 0.89). Conclusions: Treatment initiation with ergot-derived dopamine agonist bromocriptine in younger women with few comorbidities, was associated with a low absolute long-term risk of heart valve disease, not significantly different from the risk in age and sex matched population controls. Thus, indicating a low clinical yield of pre-treatment echocardiographic screening in this patient population in accordance with current guidelines.