Hypereosinophilic Syndrome Simulating an Acute Coronary Syndrome

Objectives: To report a case of hypereosinophilic syndrome which presented clinically as acute coronary syndrome. Materials and methods: We describe the case of a 69-year-old woman with acute coronary syndrome and peripheral hypereosinophilia. Results: The condition rapidly evolved to severe heart failure. Coronary disease was excluded by cardiac catheterization. Systemic corticosteroid therapy was initiated and further secondary causes of hypereosinophilia were excluded. LEARNING POINTS • Since sudden worsening with unfavourable evolution is possible, diagnosis of hypereosinophilic syndrome (HES) should not be delayed until other diagnoses have been excluded, and should be as fast as acute coronary syndrome exclusion. • If suspicion of HES is high, corticosteroid therapy should be initiated promptly, even before myocardial biopsy or cardiac magnetic resonance imaging (CMRI), because early therapy may prevent significant restrictive heart failure.