Angioscopic findings before and after thrombus-related drug-eluting stent failure.

Drug-eluting stent (DES) failure and conditions thereafter remain issues of concern despite generational advancements in DES technology. Registry data and pathological investigations have shown a variety of causes of late stent thrombosis and very late stent thrombosis. On the other hand, clinical imaging including serial studies can provide information on the conditions during the event, the previous status of the lesion, and the healing process after stent implantation. Therefore we investigated thrombus-related DES failure using coronary angioscopy (CAS), which is a robust tool for thrombus assessment. Five out of 8 thrombotic DES failures were documented during urgent repeat percutaneous coronary intervention (repeat PCI). Four patients underwent CAS before the event, and 5 patients were followed using CAS after repeat PCI for DES failure. Among these cases, there were data before and after the event in 4 patients, which highlighted various patterns of healing after repeat PCI for thrombus-related DES failure, including erosion and yellow plaque underneath the DES. The cause of thrombus formation in this series was delayed healing process, but other possible triggers included restenosis, insufficient DAPT duration, neoatherosclerosis, and vasospasm. In addition to these findings being consistent with previous segmental postmortem studies, invasive imaging modalities can provide data on more than just the event itself, such as sequential comparison and lesion features of the survivor. Accumulation of this knowledge would contribute to generating new hypothesis in the future.