Segmental Plaque Heterogeneity in a Composite Right Internal Thoracic Artery–Radial Artery Graft as Visualized by NIRS-IVUS

BACKGROUND: The internal thoracic artery has demonstrated well-established long-term patency in coronary artery bypass grafting, but the mechanisms underlying its durability remain incompletely understood. CASE SUMMARY: A man in his 70s presented with recurrent angina 23 years after bypass surgery, which had included a composite right internal thoracic artery-radial artery graft. One year postoperatively, a bare-metal stent had been implanted at the graft anastomosis. Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) showed minimal atherosclerotic change in the internal thoracic artery segment. The radial artery segment demonstrated superficial calcification without lipid accumulation, while lipid-rich neoatherosclerosis was confined to the stented anastomosis. The native right coronary artery contained extensive lipid-rich plaque and was treated with percutaneous coronary intervention. The patient was discharged without complications. DISCUSSION: NIRS-IVUS revealed segmental differences in plaque within the composite graft. TAKE-HOME MESSAGE: Composite arterial grafts may exhibit segmental plaque heterogeneity detectable by NIRS-IVUS.