Microvascular Loss and Diastolic Dysfunction in Severe Symptomatic Cardiac Allograft Vasculopathy

Background: Cardiac allograft vasculopathy (CAV) remains an important source of mortality after heart transplant. The aim of our study was to identify structural and microvasculature changes in severe CAV. Methods and Results: The study group included heart transplant recipients with severe CAV who underwent retransplantation (severe CAV, n=20). Control groups included time from transplant matched cardiac transplant recipients without CAV (transplant control, n=20), severe ischemic cardiomyopathy patients requiring left ventricular assist device implantation (ischemic control, n=18), and normal hearts donated for research (donor control, n=10). We collected baseline demographic information, echocardiography data, and performed histopathologic examination of myocardial microvasculature. Echocardiographic features of severe CAV included lack of eccentric remodeling and presence of significant diastolic dysfunction. In contrast, diastolic function was preserved in transplant control subjects. Histopathologic...