New Insights into Intravascular Imaging of Coronary Bifurcation Lesions and Left Main Stenosis:What Have We Accomplished?

Coronary bifurcation lesions(CBL)are one of the most challenging lesions to treat in interventional cardiology.Intravascular imaging including intravascular ultrasound(IVUS)and optical coherence tomography(OCT)is paramount for the assessment of lesion characteristics and suboptimal stent results and to improve the outcome of percutaneous coronary intervention(PCI).After upgrading the use of IVUS and OCT by the American College of Cardiology/American Heart Association guidelines,their use has increased.Likewise,there has been significant improvement in image quality and the profile of system(ie,IVUS catheter size).The main indication for the use of IVUS includes:assessment of lesion characteristics,optimization of stent deployment,optimal stent expansion,exclusion of plaque burden>50%,and edge dissection.Intravascular imaging plays a significant role in the assessment and treatment of left main(LM)coronary artery stenosis and CBL.In particular,the use of intravascular imaging for alleviating mechanical issues during stenting and managing stent thrombosis has significantly increased.Overall,a compelling body of evidence has shown that the use of IVUS or OCT during PCI leads to optimal stenting results and mitigates the risk of adverse cardiac events.However,to date,the American College of Cardiology/American Heart Association Guidelines have assigned a Class IIb recommendation for IVUS or OCT,while the European Society of Cardiology Guidelines upgraded it to the Class IIa recommendation.This review summarized the role of IVUS and OCT for the assessment of stenosis and stent optimization in patients with CBL and LM stenosis.In addition,we discuss new insights into the role of IVUS-and OCT-guided stenting in patients with CBL and LM stenosis provided by the ongoing randomized trials.