Coronary Artery Spasm as a Rare Manifestation of Hypereosinophilic Syndrome: A Case Report.

Hypereosinophilic syndrome (HES) is a rare hematologic disorder characterized by persistently elevated eosinophil counts, leading to organ involvement. While eosinophilic myocarditis and endocarditis are common manifestations, coronary artery spasm as a presenting feature of HES is rare. We present the case of a 41-year-old female with a 4-year history of asthma and chronic sinusitis who presented with a 6-month history of dizziness, headaches, and syncope. Despite normal brain CT and MRI, she was diagnosed with a patent foramen ovale (PFO) and underwent closure. However, her symptoms persisted, and she developed intermittent chest pain, which was relieved by nitrates. Further investigation revealed severe right coronary artery spasm, and HES was diagnosed after a comprehensive evaluation, including elevated eosinophil counts and eosinophilic infiltration in the colon. The patient was treated with prednisone, which led to normalization of eosinophil levels and resolution of her symptoms. Follow-up over 3 months showed no recurrence of dizziness or chest pain, and eosinophil counts remained within the normal range. This case highlights the importance of considering HES in the differential diagnosis of refractory coronary spasm and the value of early corticosteroid treatment. It also emphasizes the need for careful patient selection when considering PFO closure, as the procedure did not alleviate the patient's symptoms.