Three-dimensional optical frequency domain imaging in conventional percutaneous coronary intervention: the potential for clinical application

Two-dimensional (2D) frequency domain optical coherence tomography (FD-OCT) has enhanced our understanding of coronary atherosclerotic disease and is increasingly being used in conventional percutaneous coronary intervention (PCI) to elucidate mechanisms of disease and improve our understanding of complex coronary anatomy. Since the first report of three-dimensional (3D) OCT applied in human coronary vessels,1 the technology has rapidly progressed.2–10 Currently, the main limitation of this technology is the need for off-line creation of 3D reconstructions—prototypes of current generation ‘real time’ (i.e. available peri-procedurally at the ‘push-of-a-button’) remain experimental, work in progress, and are limited by relatively poor image quality/resolution.4 As of now, the potential clinical application of 3D FD-OCT remains undefined. Recently, the application of this emerging technology to the coronary bifurcation has allowed visualization and assessment of jailed side branches (SideBs) at a level of detail not previously reported.2–7 The assessment of a jailed SideB, after implantation of a bioresorbable scaffold in the main branch (MainB) of a bifurcation, lead to the proposal of a new classification system based on the assessment of the number of compartments the SideB ostium was divided into, with examples of how this may potentially effect the neointimal response and subsequent coverage of the struts.2 More recently, the application of this technology to the coronary bifurcation in patients implanted with conventional metallic stents, utilizing the Terumo optical frequency domain imaging (OFDI) system, was described for the first time.3 Hypotheses related to types of coronary bifurcation (‘parallel’ and ‘perpendicular’ bifurcations) based on the bifurcation angle, and how this leads to certain specific characteristics of the carina, which potentially made the SideB more vulnerable to the effects of carina shift and potential SideB closure, were described. Furthermore, the potential practical application of 3D FD-OCT in guiding the …