A male who were implanted bare metal stent 11 years ago were admitted for acute coronay syndrome. Optical coherence tomography showed a neointimal disruption and integrated backscatter intravascular ultrasound revealed a lipid pool around the disrupted neointima, suggesting newly formed atherosclerotic neointima developed after bare metal stent implantation. The disruption of atherosclerotic neointima may represent a new potential mechanism of very late stent thrombosis after bare metal stent implantation.
Case Description
A 63-year-old man with 2 bare metal stents (GFX 3.5/18 mm and GFX 3.0/24 mm; Medtronic, Inc., Santa Rosa, California) implanted in the left anterior descending coronary artery for 11 years was admitted to our hospital for non–ST-segment elevation myocardial infarction. Diagnostic angiography was performed, followed by optical coherence tomography and integrated backscatter intravascular ultrasound. Angiography revealed a severe stenosis within the previously implanted stents ( Figure 1 ). Optical coherence tomographic images demonstrated heterogenous neointima with disruption and large thrombus ( Figure 1 , Supplementary Video ), suggesting very late stent thrombosis caused by neointimal disruption. Intraintimal neovascularization was also observed ( Figure 1 ), which is known to be one of the characteristic findings of neoatherosclerosis after bare metal stent implantation. Then, integrated backscatter intravascular ultrasound analysis was performed for the tissue characterization of in-stent neointima. Integrated backscatter intravascular ultrasound images showed a mass of blue-colored tissue (representing a large lipid pool) within the disrupted neointima ( Figure 1 ), suggesting that vulnerable intima developed in the late phase after bare metal stent implantation.
