Percutaneous recanalization of chronic total occlusions: wherein lies the body of proof?

Although interventional technology and skills have markedly advanced, percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) lesions remains challenging. Indeed, CTO PCI is technically complex, carries the potential for a relatively high likelihood of failure and acute complications, and requires specifically skilled operators and a demanding use of resources. In addition, controversy persists surrounding appropriate indications for attempting CTO revascularization. Finally, there is a wide uncertainty on the actual benefits achieved with successful CTO recanalization. A growing number of studies have reported procedural results and/or assessed functional effects and long-term clinical outcomes of CTO PCI. We therefore sought to review and critically appraise the evidence base for procedural outcomes and potential clinical benefits of CTO PCI.