Characteristics of patients with advanced heart failure having eosinophilic infiltration of the myocardium in the recent era.

Eosinophilic infiltration of the myocardium is occasionally observed as an incidental histological finding in endomyocardial biopsy specimens before heart transplantation (HTx) as well as in explanted heart obtained at the time of HTx. However, the indications for HTx in these patients have not yet been fully established. We investigated the pre-HTx characteristics of the recipients with myocardial eosinophilic infiltration in the explanted heart and diagnosed as hypersensitivity myocarditis (HSM) (21 among 761 recipients, 2.8%). Dobutamine, a common cause of HSM, was administered to 12 patients (57%). Ten patients (47.6%) were on milrinone and 4 (19.0%) were on ventricular assist devices. Post-transplant survival of HSM patients was comparable to that of patients transplanted for active myocarditis or other cause of heart failure. In conclusion, myocardial eosinophilic infiltration is associated with multiple medications in patients with advanced heart failure; however, it does not affect the post-transplant prognosis.