Histology of the Explanted Hearts of Children Transplanted for Dilated Cardiomyopathy

There is little information as to the histology of the explanted hearts of children transplanted for presumed dilated cardiomyopathy. We therefore aimed to describe the histology of these explants. Thirty-six children [mean age 7.4 years (range 0.1-17)] transplanted for dilated cardiomyopathy were identified. Based on histological examination of the explanted hearts patients were classified into three groups: severe inflammation, mild to moderate inflammation, and minimal or no inflammation. Cell death/damage and fibrosis were also scored. Duration of symptoms and degree of support at transplant were ascertained from the case notes. Two patients had severe confluent inflammation, nine mild or moderate focal inflammation, and 25 minimal or no inflammation. The degree of inflammation and fibrosis did not correlate with the interval between presentation and transplant (p = 0.37 and p = 0.78). Patients requiring inotropes or ventricular assist had a shorter time interval between presentation and transplant (p = 0.017) although these levels of support were not associated with the degree of inflammation or fibrosis (p = 0.90 and 0.5). We conclude that the explanted hearts of one-third of children transplanted for presumed cardiomyopathy have some degree of inflammation. Histological findings are not associated with symptom duration or support required.