Is there a role for oct for left main assessment before and after PCI?

Left main (LM) coronary artery disease is a pathological condition of great clinical relevance due to its significant impact on both morbidity and mortality of patients with ischemic heart disease. An accurate assessment of the extent and characteristics of LM disease is often challenging due to the two-dimensional nature of angiography. For this reason, adjunctive techniques (i.e., intravascular imaging/functional assessment) have been introduced to aid the evaluation of LM disease severity and to guide invasive treatment. While intravascular ultrasound is still considered the invasive imaging modality of choice for the evaluation of ostial LM stenosis, optical coherence tomography (OCT) imaging, thanks to its unprecedented spatial resolution, is emerging as a valid alternative, in particular for the assessment of mid-shaft and distal LM stenosis. OCT imaging can be useful in each step of LM procedures: (1) to assess stenosis severity and to evaluate the need for revascularization; (2) to select the appropriate treatment strategy of LM bifurcation (e.g., single vs. two stents); (3) to guide all steps of percutaneous coronary intervention (PCI) (e.g., lesion preparation, decision of the landing zone, stent sizing, proximal optimization, side branch rewiring, kissing balloon); (4) to optimize stent result (e.g., expansion, apposition, geographical miss, major dissections). Although a growing body of data is already available on the use of OCT imaging for LM disease assessment and treatment, ongoing large prospective randomized trials will provide us with a more definitive evidence in this regard. These advances may substantially influence patient outcomes in what is a rapidly evolving field of coronary intervention.