Progression of a lesion with nodular calcification: serial observations by optical coherence tomography and coronary angioscopy
A 74-year-old man previously treated with a percutaneous coronary intervention (PCI) was admitted to our hospital because of effort angina pectoris. Coronary angiogram showed an in-stent restenosis (ISR) lesion at the proximal right coronary artery (Fig. 1A). At the distal site of the ISR segment (Fig. 1B), an angiographic haziness in the intermediate de-novo lesion was detected. Optical coherence tomography (OCT) showed a protruding mass with an irregular surface, high backscattering, and signal attenuation, which was concordant with a nodular calcification 1 (Fig. 1i-a and ii-a). Coronary angioscopy (CAS) showed a protruding mass with white and yellow complex material (Fig. 1i-b and ii-b). He underwent PCI for ISR successfully and became asymptomatic. Follow-up angiogram 11 months after re-PCI showed a severe luminal narrowing at the distal site of the ISR segment (Fig. 2B), which was occupied by a large amount of lipid-rich plaque on OCT (Fig. 2i-a), and a protruding bright yellow mass on CAS (Fig. 2i-b).