Aim of the study is to evaluate chronic total coronary occlusion treatment results 6 years after bioresorbable scaffold implantation by quantitative coronary analysis, intravascular ultrasound and optical coherence tomography.

The study aims to assess the outcomes of treating chronic total coronary occlusion (CTO) using bioresorbable scaffolds six years after implantation. The evaluation employs quantitative coronary analysis (QCA), intravascular ultrasound (IVUS), and optical coherence tomography (OCT) as invasive imaging tools. Clinical follow-ups were conducted at one and six years post-implantation to ensure a comprehensive understanding of the long-term safety and feasibility of bioresorbable scaffold implantation for CTO.

The primary outcome measure is defined as the target lesion failure of the treated chronic total coronary occlusion segment. Target lesion failure typically encompasses a composite endpoint that includes clinical events such as cardiac death, target vessel myocardial infarction, and clinically-driven target lesion revascularization.

The use of QCA allows for the quantitative assessment of the coronary arteries, providing measurements of vessel diameter and lesion length. IVUS is employed to obtain detailed images of the vessel wall, helping to visualize the morphology of the treated segment and assess the presence of any complications such as stent malapposition or edge dissections. OCT, with its high resolution, allows for detailed imaging of the coronary artery, providing information on plaque composition and stent apposition.

By combining these invasive imaging tools with clinical follow-ups at specified intervals, the study aims to provide a comprehensive evaluation of the long-term efficacy and safety of bioresorbable scaffold implantation in the treatment of chronic total coronary occlusion. The focus on target lesion failure as the primary outcome measure ensures a clinically relevant assessment of the success of the intervention.

Inclusion Criteria:

• 100% occlusion of a coronary artery for a duration of greater than or equal to 3 months based on angiographic evidence.

Exclusion Criteria:

• Participant withdrawal from study.