Summary

A 65-year-old lady and a 69-year-old gentleman, both with a background history of adult-onset asthma, presented with clinical features of heart failure (HF). High-sensitivity cardiac troponin T and eosinophils were significantly raised, along with poor left ventricular (LV) systolic function on cardiac imaging. Endocardial and skin biopsy (in cases 1 and 2, respectively) showed eosinophilic infiltration. This in combination with the clinical features confirmed the diagnosis of eosinophilic myocarditis (EM) secondary to eosinophilic granulomatosis with polyangiitis in case 1. Both cases were managed with high-dose intravenous corticosteroids and conventional HF medication. Case 1 successfully responded clinically with improvement in LV systolic function. Case 2 required further immunosuppressive therapy (rituximab) and cardiac resynchronisation therapy, but eventually died of septic shock secondary to immunosuppressives. Our cases highlight the importance of early diagnosis and treatment of EM and ongoing monitoring of patients on immunosuppressive therapy.