Coronary restenosis of in-stent protruding bump with rapid progression: Optical frequency domain imaging and angioscopic observation.

In-stent restenosis (ISR) remains a tough problem after percutaneous coronary intervention (PCI) despite advances in technology of drug-eluting stents (DES). A 63-year-old man undergoing hemodialysis was diagnosed with non-ST elevation acute coronary syndrome (NSTE-ACS). An emergency coronary angiography (CAG) revealed severe stenosis in the middle left circumflex artery (LCx). After pre-dilatation with non-compliant balloon, primary PCI was successfully performed with DES implantation. Four months after, CAG was performed again and verified ISR of LCx under diagnosis of recurrent NSTE-ACS. Subsequently multimodality intravascular imaging assessment was performed for the ISR lesion. Optical frequency domain imaging showed the eccentric protruding mass with irregular surface with high-backscatter, whereas angioscopy revealed the in-stent bump with yellow color. The ISR lesion was successfully treated by drug-coated balloon angioplasty. However, he suffered recurrent NSTE-ACS five months later. CAG revealed de novo stenotic lesions not only in re-restenosis of LCx but also in proximal left anterior descending artery and ostium of right coronary artery. He was scheduled to undergo coronary artery bypass grafting for three-vessel disease. Multimodality assessment is useful to diagnose the recurrent restenosis lesion with calcified nodule. <Learning objective: In-stent restenosis (ISR) is rarely recurrent even after drug-eluting stent (DES) implantation. In-stent protruding bump is observed in types of ISR morphology by intravascular imaging, and the finding suggests the possibility of recurrent ISR. Diagnosis of the morphology is sometimes difficult, but multimodality imaging assessment is useful to distinguish the ISR tissue.>.