The Role of Percutaneous Coronary Intervention in the Treatment of Chronic Total Occlusions: Rationale and Review of the Literature

Background: Chronic total occlusion (CTO) of a coronary artery is defined as an occluded segment with no antegrade flow and a known or estimated duration of at least 12 weeks. Objective: We considered the current literature describing the indications and clinical outcomes for denovo CTO- percutaneous coronary intervention (PCI), and discuss the role of CTO-PCI and future directions for this procedure. Methods: Databases (PubMed, the Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL were searched and relevant studies of CTO-PCI were selected for review. Results: The prevalence of coronary artery CTO's has been reported to be ~ 20% among patients undergoing diagnostic coronary angiography for suspected coronary artery disease. Revascularization of any CTO can be technically challenging and a time-consuming procedure with relatively low success rates and may be associated with a higher incidence of complications, particularly at non-specialized centers. However, with an increase in experience and technological advances, several centers are now reporting success rates above 80% for these lesions. There is marked variability among studies in reporting outcomes for CTO-PCI with some reporting potential mortality benefit, better quality of life and improved cardiac function parameters. Anecdotally, properly selected patients who undergo a successful CTO-PCI most often have profound relief of ischemic symptoms. Intuitively, it makes sense to revascularize an occluded coronary artery with the goal of improving cardiovascular function and patient quality of life. Conclusion: CTO-PCI is a rapidly expanding specialized procedure in interventional cardiology and is reasonable or indicated if the occluded vessel is responsible for symptoms or in selected patients with silent ischemia in whom there is a large amount of myocardium at risk and PCI is likely to be successful.