Angiography is the current standard method to guide PCI strategy in clinical practice. However, angiography has a number of well-described limitations, primarily through only providing an assessment of luminal dimensions without delineation of the burden of atheroma-tous disease. Angiography also provides suboptimal assessment of post PCI complications such as stent underexpansion or malapposi-tion, residual dissections or thrombus, and tissue prolapse. These limi-tations may be overcome in part by intravascular imaging (IVI), which allows tomographic, cross-sectional imaging of the vessel wall. Meta-analyses of randomized and registry studies of IVI-guided vs. angi-ography-guided PCI have suggested that IVI-guidance may improve clinical outcome following PCI.~Optical coherence tomography (OCT) provides high-resolution (10-20 μm) cross-sectional images of plaque microarchitecture, stent place-ment and size and strut coverage. Recently the MLD-MAX algorithm was developed to guide and stand-ardize coronary stent implantation based on sizing of the vessel at the proximal and distal reference using the EEL.
The study aims to assess contemporary practice in OCT use during routine interven-tional practice and to assess the impact of the MLD-MAX algorithm on real-world PCI in a large unselected European all-comer-study cohort.