The goal of this observational study is to evaluate the safety, efficacy, and clinical outcomes of percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) in patients treated in contemporary clinical practice in Poland.

The main questions it aims to answer are:

• What are the rates of procedural success and periprocedural complications of CTO PCI in routine clinical practice?
• How do CTO PCI strategies and techniques, intravascular imaging, different treatment strategies, and mechanical circulatory support affect clinical outcomes?
• How do clinical outcomes differ among different patient subgroups?
• Can artificial intelligence-based analysis predict clinical and quality-of-life outcomes after CTO PCI?

Patients undergoing CTO PCI as part of their standard medical care will be prospectively enrolled in a national, multicenter registry, with clinical, procedural, and follow-up data collected to evaluate real-world outcomes.

Coronary chronic total occlusions (CTO) are diagnosed in approximately 20% of patients undergoing invasive coronary angiography, and their presence is associated with significantly reduced quality of life and worse long-term prognosis compared with patients without a CTO. Successful CTO recanalization improves quality of life, regional and global left ventricular function, and reduces myocardial ischemia in most patients. Over the past decade, the success rate of percutaneous coronary intervention (PCI) for CTO has increased substantially, largely due to advances in dedicated equipment and specialized procedural techniques. Concurrently, there is a growing need to evaluate the safety and effectiveness of contemporary CTO PCI techniques in selected patient populations.

The aim of the POL-CTO registry is to expand current knowledge regarding the safety and efficacy of CTO PCI in the contemporary Polish population across a broad range of clinical scenarios. Specifically, the registry will examine the incidence and management of periprocedural complications, as well as the impact of post-procedural cardiac injury markers on clinical outcomes. Comparative analyses of PCI performed with versus without intravascular imaging, along with different treatment strategies (drug-coated balloon [DCB], drug-eluting stent [DES], or hybrid approaches), will be conducted. Additional objectives include evaluating the safety of PCI with mechanical circulatory support and predicting quality-of-life improvement using artificial intelligence-based analysis of baseline electrocardiograms. Finally, the study will focus on CTO PCI outcomes in high-risk subgroups, including patients with low ejection fraction, frailty syndrome, severe coronary calcification, diabetes, prior transcatheter aortic valve implantation, prior coronary artery bypass grafting, and in-stent CTO.

Inclusion Criteria:

• Patients undergoing CTO PCI based on clinical grounds

Exclusion Criteria:

• Age <18 years
• Patient's refusal to participate in the registry

Consecutive patients undergoing CTO PCI at participating centers.