Synopsis of Clinical Coronary Artery Imaging

Abstract

Coronary angiography is the gold standard for direct evaluation of the coronary anatomy but is limited by the inability of the derived «lumenogram» to visualize the arterial wall per se. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) were developed to overcome this limitation. These intracoronary imaging modalities have moved beyond the framework of research and are formally recommended in current guideline documents for clinical use in properly selected patients. In clinical research, intracoronary imaging has enabled assessment of serial changes of the atherosclerotic disease burden under the influence of proatherogenic risk factors or antiatherosclerotic medications, and has uniquely allowed for evaluation of plaque morphology and composition in vivo. In real-world interventional practice, IVUS and OCT are used to enhance preintervention lesion assessment, guide percutaneous coronary intervention, optimize the procedural result, and determine mechanisms underlying stent failure (restenosis or thrombosis). Beyond the well-established ability of IVUS and OCT to improve the acute procedural result, recent randomized trial evidence points to improved clinical outcomes following IVUS-guided versus angiography-guided coronary interventions. Currently, intracoronary imaging techniques have found their place in the catheterization laboratory and are increasingly being used to inform clinical decision making, particularly in challenging patient and lesion subsets. Properly designed studies are warranted to define the relative merits of each modality, further expand the indications for peri-interventional IVUS and OCT, determine the clinical relevance of various abnormal findings, and establish standardized criteria for corrective measures in response to the imaging outcome.