title: Predicting successful guidewire crossing through chronic total occlusion of native coronary lesions within 30 minutes: the J-CTO (Multicenter CTO Registry in Japan) score as a difficulty grading and time assessment tool.
abstract: OBJECTIVE
  This study sought to establish a model for grading lesion difficulty in interventional chronic total occlusion (CTO) treatment.
  
  
  BACKGROUND
  Owing to uncertainty of success of the procedure and difficulties in selecting suitable cases for treatment, performance of interventional CTO remains infrequent.
  
  
  METHODS
  Data from 494 native CTO lesions were analyzed. To eliminate operator bias, the objective parameter of successful guidewire crossing within 30 min was set as an end point, instead of actual procedural success. All observations were randomly assigned to a derivation set and a validation set at a 2:1 ratio. The J-CTO (Multicenter CTO Registry of Japan) score was determined by assigning 1 point for each independent predictor of this end point and summing all points accrued. This value was then used to develop a model stratifying all lesions into 4 difficulty groups: easy (J-CTO score of 0), intermediate (score of 1), difficult (score of 2), and very difficult (score of ≥ 3).
  
  
  RESULTS
  The set end point was achieved in 48.2% of lesions. Independent predictors included calcification, bending, blunt stump, occlusion length >20 mm, and previously failed lesion. Easy, intermediate, difficult, and very difficult groups, stratified by J-CTO score, demonstrated stepwise, proportioned, and highly reproducible differences in probability of successful guidewire crossing within 30 min (87.7%, 67.1%, 42.4%, and 10.0% in the derivation set and 92.3%, 58.3%, 34.8%, and 22.2% in the validation set, respectively). Areas under receiver-operator characteristic curves were comparable (derivation: 0.82 vs. validation: 0.76).
  
  
  CONCLUSIONS
  This model predicted the probability of successful guidewire crossing within 30 min very well and can be applied for difficulty grading.
authors.affiliation: Division of Cardiology, Tokai University School of Medicine, Isehara, Japan. ymorino@is.icc.u-tokai.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Morino
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Abe
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Toshiya
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ochiai
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kato
authors.forename: Yoshisato
authors.initials: Y
authors.lastname: Shibata
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hiasa
authors.forename: Osamu
authors.initials: O
authors.lastname: Doi
authors.forename: Takehiro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Hinohara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Mitsudo
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects; D016009:Chi-Square Distribution; D002908:Chronic Disease; D017023:Coronary Angiography; D054059:Coronary Occlusion / Q000000981:diagnostic imaging / Q000628:therapy*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome