This registry will include consecutive patients presenting with at least one chronic total occlusion on coronary angiogram who will be treated by percutaneous coronary intervention in our center. All patients will undergo a non-invasive assessment for myocardial ischemia/viability using cardiac magnetic resonance (CMR) prior to revascularization therapy. Follow up CMR will be repeated in all participants after three months and one year. Additionally, clinical outcomes and quality of life will be evaluated at baseline and at follow-up. Primary objective of this study is to investigate the the reduction in ischemia (as evaluated by follow-up CMR) and the severity of angina according to clinical evaluation (including Seattle Angina Questionnaires [SAQ], Canadian Class Score[CCS] and 6-mins walking test).

Inclusion Criteria:

• Age > 18 years
• Presence of at least one untreated CTO at basal angiography (defined as a total occlusion in any major coronary vessel or relevant side branches [reference vessel diameter ≥2.5mm or as judged by two independent interventional cardiologists], with TIMI 0 in the distal segment and at least 3 months old
• Patient has a clinical indication to perform CTO PCI
• Willing to participate and able to understand, read and sign the informed consent document.

Exclusion Criteria:

• CMR contraindications
• Contraindications to adenosine or dobutamine
• Severe chronic kidney disease (estimated Glomerular Filtration Rate [eGFR] <60 mL/min/1.73m2 or serum creatinine level >2.5 mg/dL)

The study population includes patients presenting with a diagnose of coronary chronic total occlusions undergoing percutaneous coronary intervention.