**13. Ongoing randomized CTO trials**

Most of the clinical outcome data of CTO interventions derives from retrospective analyses and registry data. Prospective randomized controlled trials such as the DECISION-CTO trial (Drug-Eluting Stent Implantation Versus Optimal Medical Treatment in Patients with Chronic Total Occlusion) and the EURO-CTO trial (European Study on the Utilization of Revascularization versus Optimal Medical Therapy for the Treatment of Chronic Total Coronary Occlusions) are largely missing and eagerly awaited. Other trials such as the REVASC trial investigate left ventricular function before and after successful CTO PCI.
