Cath Lab DigestBeyond Angiography: The Power of IVUS + NIRS in PCI

🎓 Expert Commentary / Peer Perspective

Angiography characterizes luminal stenosis but does not reliably identify plaque burden, morphology, or vulnerable plaque. Intravascular imaging-guided PCI carries a Class 1A recommendation in the 2025 ACC/AHA coronary imaging guidelines, supported by meta-analyses across tens of thousands of patients showing improvements in stent sizing, lesion preparation, and major adverse cardiac event rates.

Clinical Considerations

• IVUS combined with NIRS can distinguish lipid-rich and calcific plaque subtypes not visible on angiography, including eruptive versus traditional calcified nodules
• Plaque burden greater than 50% and LCBI greater than 108 at the distal stent edge are associated with increased target vessel failure risk (PROSPECT II substudy)
• In angiographically ambiguous NSTEMI, intravascular imaging may identify culprit lesions that would otherwise be managed medically
• Severely calcified lesions represent an estimated 30%+ of current PCI cases; imaging-guided lesion preparation (atherectomy, IVL) is guided by calcium arc, density, and distribution
• AI-assisted IVUS measurement tools are emerging as workflow aids, though independent validation across systems remains limited

Practice Applications

• Consider intravascular imaging in angiographically hazy or moderate lesions, particularly in NSTEMI presentations where culprit identification is uncertain
• Assess distal stent edge plaque burden and lipid content before accepting final PCI result, especially in long-segment disease
• Recognize calcification subtype (arc, eccentricity, nodule morphology) when selecting lesion modification strategy
• Integrate intravascular imaging into complex PCI workflows in alignment with current Class 1A ACC/AHA guidance