Severe Autoimmune Hyperthyroidism in Two Patients with Pulmonary Arterial Hypertension after Treatment with Epoprostenol

Objective: To highlight the increased risk of severe hyperthyroidism leading to decompensation of pulmonary and cardiac hemodynamics post initiation of epoprostenol for treatment of pulmonary arterial hypertension (PAH). Methods: Review of literature shows an increased incidence of autoimmune thyroid disease in patients undergoing treatment of PAH with epoprostenol. We describe two incidences of seropositive thyrotoxicosis associated with acute decompensation of pulmonary and cardiac function. Results: We report two patients with no prior history of thyroid disease who developed severe hyperthyroidism after initiation of epoprostenol. Conclusions: Clinicians should be aware of the potential for development of severe hyperthyroidism leading to rapid decompensation in cardiac and respiratory status after initiation of epoprostenol in patients with PAH. Rapid development of compressive goiter in those treated with prostacyclins is also possible.