Intravascular ultrasound (IVUS) serves as a beneficial instrument during percutaneous coronary intervention (PCI) procedures, affording insight into lesion characteristics and stent implantation. The ULTIMATE trial recently evidenced that IVUS-guided Drug-Eluting Stent (DES) implantation notably ameliorated clinical outcomes in all-comers, especially in patients who underwent an optimal procedure defined by IVUS, as opposed to angiography guidance, resonating with findings from the IVUS-XPL study, OCTOBER trial, and RENOVATE COMPLEX PCI trial, further confirmed by more recent IVUS-ACS trial. Optical coherence tomography (OCT) has a resolution 10 times higher than that of IVUS and can provide valuable information at each step of PCI. Regrettably, a dearth of prospective, randomized, multicenter trials exists that scrutinize the benefits of IVI-guided as opposed to angiography-guided PCI in patients suffering from diabetes mellitus. However, several trials have presented subgroup analyses reporting the reduction of clinical events by IVUS but not OCT guidance in patients with diabetes mellitus, which served as the foundation for the design of this trial.