Autopsy findings of Amplatzer septal occluder at 5 months after closure of atrial septal defect: how long does it take to be endothelialized?

An 83-year-old man died of aspiration pneumonia 5 months after closure of atrial septal defect (ASD) with an Amplatzer atrial septal defect occluder (ASO). At autopsy, the device was scarcely covered by the endothelium. After percutaneous ASD closure, 6-month course of antiplatelet therapy and prophylaxis for endocarditis are recommended. However, the 6-month duration may not be sufficient for some patients. More data are required to clarify how long it takes for the ASO device to be endothelialized in the human body and to determine predictors of poor endothelialization.