J-CTO score for native coronary chronic total occlusions
Multicenter CTO Registry in Japan has established as scoring system known as J-CTO score which can grade the difficulty in crossing a chronic total occlusion (CTO) of a native coronary lesion . The score was derived from the analysis of nearly five hundred native CTO lesions. Operator bias was excluded by setting successful guidewire crossing within thirty minutes rather than actual procedural success as the cut off point. The J-CTO score was derived by giving one point each for independent predictors of this end point and adding up all the points together. The difficulty in crossing the lesions were stratified into easy, with J-CTO score of zero, intermediate, with score of one, difficult with score of two and very difficult if the scores were three or more. The end point was reached in about half of the lesions. The important independent predictors were calcification, bending, blunt stump, length of occluded segment more than twenty millimeters and previously failed lesions. The probability of crossing the lesion with guide wire in thirty minutes was nearly eighty eight percent with easy lesions, while it was just ten percent with very difficult lesions. The intermediate group had a probability of about sixty seven percent while the difficult group had a chance of about forty two percent.
- Morino Y et al. 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. JACC Cardiovasc Interv. 2011;4:213-21.