Intravascular ultrasound as an adjunct tool for angiographically intermediate lesions and complex coronary interventions: patient selection and perspectives

Abstract

Intravascular ultrasound (IVUS) provides valuable anatomic information about the coronary arterial lumen, wall, and plaques that cannot be assessed by coronary angiography alone. For over 2 decades, IVUS has been shown to be a helpful tool for identifying significant ischemia in angiographically intermediate left main (LM) or non-LM lesions by measuring the minimum luminal area. It can also guide percutaneous coronary intervention (PCI) in complex coronary lesions such as LM, bifurcation, chronic total occlusion, in-stent restenosis, and long or calcified lesions. In these complex lesions, IVUS can reduce stent thrombosis or restenosis by accurate lesion assessment and detection of stent underexpansion, malapposition, or edge dissections. Through further intervention based on these IVUS findings, optimal stent deployment can be achieved. IVUS can also identify the culprit lesion with plaque rupture, and vulnerable lesions with a large plaque burden or thin-cap fibroatheroma. Although other new imaging modalities with improved resolution and technologies are attracting increased clinical attention, IVUS remains the most reliable intracoronary imaging modality to guide PCI until other new imaging devices are proven to be useful and improve clinical outcomes. However, current data on clinical utility are conflicting and the guidelines do not recommend routine use of IVUS when performing angiography or PCI. In this review, we focus on issues related to the selection of patients who might benefit from IVUS guidance and discuss future perspectives on intracoronary imaging.