The current generation of drug eluting stents (DESs) has several advantages over the previous generations of DESs and bare metal stents (BMSs) and offers good efficacy and safety. However, the risk of stent thrombosis remains, and the stented vessel remains permanently associated with a rigid metal cage. Bioresorbable vascular scaffolds (BRSs) have recently reenergized the field of coronary intervention; they support transient drug delivery and vessel patency and then gradually tend to complete resorption [1, 2]. Therefore, BRSs might allow restoration of vasomotion and distensibility [3] and may exclude stent thrombosis, “jailing” of the side branches, and struts overhanging over ostial lesions. They may also obviate the inability to surgically graft stented segments [4]. Optical coherence tomography (OCT) has played a major role in the development of BRS technology by providing more precise and detailed morphologic information (compared to IVUS) as a result of its higher resolution [5–8]. While the clinical outcome data from the landmark BRS trials are promising [9–11], the studies had numerous limitations regarding patient and lesion selection. There are a paucity of data on BRS implantation in unselected patient population in “real world” clinical practice, including in-stent restenosis, bifurcation, and severely calcified lesions [12–14]. Similar to metallic stents, suboptimal implantation with incomplete lesion coverage, scaffold underexpansion, and strut malapposition have been the main pathomechanisms for both early and late BRS thrombosis [15]. OCT imaging can help optimize BRS sizing and guide postdilation in order to avoid scaffold underexpansion or fracture.

For metallic stents, OCT has demonstrated exquisite capability to clarify abnormal angiographic findings, including peristrut contrast staining and intraluminal filling defects. Abnormal coronary dilatation at the site of DES implantation demonstrating contrast staining outside the stent struts, peri-stent contrast staining (PSS) , has been shown to be associated with target-lesion revascularization and very late stent thrombosis [16]. OCT can differentiate between two main underlying causes of PSS, incomplete stent apposition and multiple interstrut hollows or cavities between well apposed stent struts [17]. Intraluminal filling defects are occasionally observed on coronary angiography, and thrombosis has often been used as a default diagnosis; however, there are many different causes responsible for the phenomenon, including calcification, dissection, plaque rupture, and artifacts [18]. OCT allows accurate characterization angiographic filling defects and provides important information for treatment optimization.