Increase in J-CTO lesion complexity score explains the disparity between recanalisation success and evolution of chronic total occlusion strategies: insights from a single-centre 10-year experience

Objective To investigate whether treatment of lesions of greater complexity is now undertaken and to assess the rates of procedural success per class of lesion complexity. Design Observational study. Setting Despite impressive progress in treatment strategies and equipment, the success rate of percutaneous coronary intervention for chronic total occlusion (CTO) has remained relatively stable. Participants 483 patients consecutively treated with CTO from 2003 to 2012. Main outcome measures The Multicenter CTO Registry of Japan (J-CTO) score was used to classify lesion complexity. The study population was subdivided into an early (period 1, n=288) and a late (period 2, n=195) period according to the routine implementation of novel techniques and advanced equipment. Results Period 2 was marked by more ‘difficult’ and ‘very difficult’ lesions (J-CTO grades 2 and 3) being attempted, with procedural success increasing from 68.4% to 88.1% (p