Prediction and assessment of the long-term outcomes of coronary chronic total occlusion-percutaneous coronary intervention

Soichiro Ebisawa

Coronary Chronic Total Occlusions (CTOs) are completely occluded coronary arteries that have no antegrade coronary flow for an estimated duration of at least 3 months. Although Percutaneous Coronary Intervention (PCI) for CTO lesions (CTO-PCI) has a lower success rate and a higher complication rate than PCI for nonocclusive lesions, owing to recent improvements in devices and strategies, CTO-PCI may be a valid strategy for patients with ischemic heart disease. The clinical benefits of CTO-PCI have remained ambiguous because most investigations on CTO-PCI are non-randomized observational trials that compared successful and unsuccessful cases of CTO-PCI. Recent randomized controlled trials that compared CTO-PCI and optimal medical therapy or the non-use of CTO-PCI failed to reveal the clinical benefits of CTO-PCI. Although the initial success rate of CTO-PCI was improved, no obvious indication for CTO-PCI was established, except for the relief of symptoms and the improvement of quality of life. However, there are cases in which CTO-PCI provides significant benefits in daily practice.

The following actions are required to establish the validity of CTO-PCI:

1) Determining indications for which CTO-PCI would result in the most favorable outcomes and

2) Developing standardized pre-procedural risk assessment tools that can assist the identification of patients who are at a high risk of developing long-term clinical events.