Acute coronary syndrome secondary to in-stent plaque rupture occurred at 9 years after deployment of bare metal stent.

We report a case with acute coronary syndrome due to in-stent plaque rupture that occurred 9 years after bare metal stent deployment. From the results of intravascular imaging and pathological findings, we diagnosed this case as acute coronary syndrome caused by in-stent plaque rupture. In-stent neoatherosclerosis is an important mechanism of very late stent thrombosis, and the intravascular imaging is helpful to identify this and to decide clinical judgment. <Learning objective: In-stent neoatherosclerosis is an important mechanism of very late stent thrombosis, and the intravascular imaging is helpful to identify this and to decide clinical judgment.>.