European Medical Journal (Aug 2017)
Contemporary Evidence, Treatment Strategies, and Indications for Chronic Total Occlusion-Percutaneous Coronary Intervention
Abstract
Chronic total occlusions (CTOs) are detected incidentally in ˜20% of patients undergoing coronary angiography and are often associated with significant morbidity and mortality. CTOs can manifest with worsening symptoms, reduced left ventricular function, and increased incidence of ventricular arrhythmias. Despite this, according to USA, Italian, and Japanese national registry data, only ~5–22% of CTO lesions are treated by percutaneous coronary intervention (PCI). CTO-PCI is a particularly challenging technique for this subset of lesions and has traditionally been associated with increased risks and complications compared to conventional PCI. However, increased experience, the development of novel techniques, and dedicated equipment have revolutionised CTO-PCI. USA, Italian, and Japanese registry data have shown success rates of between 85% and 90%, with diminishing complication rates when performed by experienced operators. Moreover, observational studies have suggested that there are significant benefits of using CTO-PCI, including fewer symptoms, improved quality of life, reduced need for coronary artery bypass surgery, and reduction in ischaemic burden and mortality. In addition, when there is demonstrable ischaemia and viable myocardium in the CTO territory, there is further potential prognostic benefit from complete revascularisation. However, there has so far been a relative lack of randomised trial data to support the routine use of CTO-PCI. This paper reviews the current evidence surrounding this subject and discusses the arguments for and against CTO-PCI. It includes an exploration of the interventionalist’s ‘toolbox’ and the techniques used in CTO-PCI, including a section on ‘tips and tricks’ for the most challenging cases. Finally, there is a discussion on the future of CTO-PCI including promising ongoing clinical trials and novel equipment that may improve outcomes and help to establish a more widespread adoption of CTO-PCI.
