Clinico-pathologic findings in end-stage pediatric heart transplant grafts

The pathologic patterns existing in end-stage pediatric heart transplant grafts may help explain the symptoms and changes seen by echocardiography and angiography in these children. Retrospective chart review and pathologic study of explanted heart grafts was performed on 12 patients that had undergone 14 heart re-transplantations. Clinical status, echocardiographic and catheterization data at the time of transplantation were correlated to the pathologic findings. At re-OHT, eight were inpatients with heart failure symptoms and/or inotropic support requirements. Echocardiograms were abnormal in all prior to re-OHT with significant diastolic dysfunction, but LVEF >40% in all but one. There was significant epicardial fibrosis in all grafts, and all had severe CAV of epicardial arteries. However, intramyocardial coronary disease was mild in nine (64%) grafts. Moderate or severe interstitial fibrosis occurred in only three grafts, and in a perivascular distribution in eight. End-stage pediatric heart allografts have severe epicardial CAV and epicardial fibrosis, with relative sparing of the myocardium. Epicardial disease with sparing of the myocardium may explain the restrictive hemodynamics and relatively preserved systolic function present in these grafts at the time of re-OHT.