Coronary Chronic Total Occlusion (CTO): A Review.

Coronary artery chronic total occlusions (CTO) are frequently encountered during coronary angiography; however percutaneous recanalization has historically been technically challenging and an important determinant for referral to coronary artery bypass surgery or for medical therapy alone. Recent advances in interventional equipment and innovative approaches to crossing CTO have significantly increased the success rate of percutaneous treatment. Although there is only one relevant randomized control trial (RCT) performed to date, several large, nonrandomized studies have consistently reported improvement in clinical outcomes, including improved survival and relief of angina, when successful percutaneous treatment of CTO was compared with unsuccessful revascularization. These positive observational results have encouraged the initiation of several RCTs which will provide more robust evidence on clinical outcomes of CTO-PCI compared with guideline-directed medical therapy (GDMT) alone.