A universal classification system for chronic total occlusions.

Notwithstanding the advances in technology in the field of interventional cardiology, treatment of chronic total occlusions (CTOs) remains a challenging obstacle, posing a considerable barrier to achieving successful complete revascularization. We are proposing a new classification system for an antegrade approach to treat CTOs that will enable interventional cardiologists to assess the technical difficulties as well as procedural risks prior to attempting percutaneous treatment of this complex lesion subset. Furthermore, this classification may be a useful tool from the research standpoint, particularly in assessing the impact of this classification on clinical success rates.