Pergolide associated cardiac valvulopathy based on Ontario administrative data

Introduction: Pergolide is an ergot derived dopamine agonist that is widely used for the treatment of Parkinson's disease. Studies have found an association between pergolide and valvular heart abnormalities although there is still much to be learned about the clinical significance of the valvular changes, who is at risk, and whether there is duration of exposure effect. Objective: To assess the long term risk of hospital admissions for valvular heart disease (VHD) or congestive heart failure (CHF, a clinically overt outcome of VHD) in new users of pergolide compared to new users of levodopa. The secondary objective was to assess whether there are any characteristics that can predict who is at higher risk of developing this outcome. Design: Retrospective, population-based cohort study. Setting: Ontario, Canada. Subjects: Ontario residents aged 66 and older, newly started on treatment with either pergolide or levodopa. Outcomes: Admission to hospital with the most responsible diagnosis of congestive heart failure or valvular heart disease. Results: The risk for admission for valvular heart disease or congestive heart failure were higher in those with 1-4 years exposure to pergolide compared with no exposure to pergolide (VHD: hazard ratio 2.4, p = 0.04; CHF: hazard ratio 1.6, p =0.02). No such pattern was found with exposure to levodopa. Conclusion: Our study demonstrates that treatment with pergolide is associated with a higher risk of hospital admission for valvular heart disease or congestive heart failure and that this risk is greater in those with 1-4 years exposure than in those with less exposure. We did not find an increased risk beyond four years.