Predictive performance of J‐Calc‐CTO score for guidewire crossing through chronic total occlusion lesions within 30 minutes: J‐CTO score modified by computed tomography coronary angiography

The original J-CTO score predicts the difficulty of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions, but the grade of calcification has not been fully evaluated. We examined 137 patients (141 CTO lesions) who underwent coronary computed tomography angiography (CTA) pre-PCI between October 2016 and October 2021. They were randomly divided into derivation (n = 94) and validation (n = 47) groups. The degree and distribution of calcification in the occluded segment were assessed using CTA. The calcified index was defined as calcium volume divided by the length of the occluded segment. We created the J-Calc-CTO score consisting of calcification parameters associated with 30-min wire crossing in the derivation group. The validity of the J-Calc-CTO score was compared with that of the original J-CTO score using c-statistics. The procedural success rate was 96%, and 30-min wire crossing during the procedure was achieved in 29%. Dense calcification (calcified-index12) (odds ratio [OR]: 4.63; 95% confidence interval [CI]: 1.24-22.2; p = 0.04) and calcification in the center of the lumen (OR: 7.25; 95% CI: 1.48-32.1; p = 0.02) were independently associated with 30-min wire crossing as variables evaluated using CTA. The J-Calc-CTO score was created by adding 1 point to the two parameters in place of "calcification" in the original J-CTO score. The J-Calc-CTO score showed a higher predictive value of 30-min wire crossing than the J-CTO score in the derivation (c-statistics; 0.836 vs. 0.670; p 0.01) and validation groups (c-statistics; 0.879 vs. 0.767, p 0.01). The degree and distribution of calcification evaluated using CTA refined the predictive value of the original J-CTO score for 30-min wire crossing.