Scoring system

Specific features

J-CTO score

ž First and widely used

ž Applicable both for antegrade and retrograde approach

ž Operator bias excluded

CT RECTOR score

ž Non-invasive

ž Operator bias excluded

ž Severe calcification used as predictor

ž Multiple occlusions were best seen by coronary CTA

CL score

ž Both clinical and angiographic parameters

ž Only the first attempt included

ž Applicable mostly for antegrade approach

PROGRESS CTO score

ž Not include prior CTO PCI failure

ž Applicable for hybrid approach

ž Final angiographic success as primary endpoint

ž Circumflex CTO as an independent predictor

ORA score

ž Simple and easy to remember

ž Only 3 variables

ž Applicable both for antegrade and retrograde approach

ž Included clinical and angiographic parameters

Ellis score

ž Improved model with powerful predictors

ž Applicable for hybrid approach

ž Complex definition for interventional collateral vessels

ž Operator G as an independent predictor