This is a prospective, randomized, controlled trial comparing two strategies for optimizing stent implantation during bifurcation stenting of the left main coronary artery (LM): an intravascular ultrasound (IVUS)-guided approach versus a "IVUS-trained eye" approach based on angiographic assessment and operator experience. All patients receive the same stent brand and procedure steps to minimize variability. The primary objective is to compare the planimetric stent appearance between two strategies.

Stenting of the left main coronary artery in bifurcation lesions remains one of the most technically demanding tasks in interventional cardiology. Stent implantation quality is directly linked to the risk of adverse outcomes. Minimal stent area (MSA), as measured by IVUS, is a key predictor of adverse clinical outcomes. In practice, however, many centers continue to rely on angiographic assessment alone when performing various left main bifurcation stenting techniques. Proponents of this approach cite extensive clinical experience, anatomical familiarity, and IVUS-informed intuition developed over time (a "trained eye"). To date, no randomized data exist comparing outcomes of left main stenting between an IVUS-guided approach and a visually/experience-guided approach. Investigators hypothesize that, when combined with mandatory bifurcation optimization steps (e.g., proximal optimization technique [POT], kissing balloon inflation [KBI]), an angiography-only approach performed by an IVUS-experienced physician is non-inferior to a standard IVUS-guided approach, as assessed by post-PCI IVUS stent planimetric characteristics.

Inclusion Criteria:

• De novo lesion in an unprotected left main coronary artery, indicated for bifurcational stenting (provisional or 2-stent)
• Patient referred for elective or delayed (non-emergency) stenting
• Technical feasibility of performing IVUS
• Signed informed consent

Exclusion Criteria:

• ST-elevation myocardial infarction (STEMI) within the preceding 72 hours
• Cardiogenic shock
• Isolated (non-bifurcation) left main lesion
• Prior PCI in the target segment
• Diameter of one of the left main main branches < 2 mm
• Occlusion in the proximal segment of one of the main left main branches without the possibility of simultaneous recanalization
• History of coronary artery bypass grafting (CABG)
• Severe comorbidity with expected life expectancy < 1 year
• Participation in another interventional study
• Patient is a woman who is pregnant or nursing;
• Female patient of childbearing potential, i.e. who are not surgically sterile or post-menopausal (defined as no menses for 2 years without an alternative cause);
• IVUS is strictly required for pre-PCI lesion severity assessment
• Patients unable to tolerate, obtain or comply with dual antiplatelet therapy for at least 6 months in stable patients and 1 year in ACS patients;
• Known contraindication or hypersensitivity to everolimus, platinum-chromium, or to anticoagulants.

Demographic, clinical, procedural and follow-up data. No personal data will be shared