D-54 | Validation of the J-Channel Score for Retrograde Channel Crossing in the PROGRESS-CTO registry

J-Channel score was developed based on the Japanese expert registry to predict successful collateral channel crossing for retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We evaluated the external validity of J-Channel score in an international registry (PROGRESS-CTO [NCT02061436]). Mean age was 62.7 ± 10.2 years, and most patients were men (81.1%). The most common target vessel was the right coronary artery (80.2%), followed by the left anterior descending coronary artery (15.6%) and left circumflex coronary artery (4.2%). Mean J-CTO score and PROGRESS-CTO scores were 2.92 ± 1.06 and 1.07 ± 0.82, respectively. The most common CC type was septal (81%), followed by non-septal CC (epicardial CC [17.4%], bypass graft CC [1.5%]). When compared with the derivation population, the PROGRESS-CTO patients had lower CC wire crossing success for easy difficulty grade based on both septal and non-septal J-Channel scores, and higher CC wire crossing success rates for intermediate and difficult grades (Figure 1 A, B). The discriminative capacities (C-statistic) of the J-Channel score in the PROGRESS-CTO registry were: 0.65 (95% confidence intervals [CI]: 0.63-0.68) for successful wire crossing (Figure 1C), and 0.65 (95% CI: 0.63-0.68) for successful microcatheter crossing (Figure 1D). The interrater reliability (Κ-statistic) of the J-Channel score were: 0.41 (p<0.001) for septal and 0.43 (p=0.005) non-septal CCs. The predictive efficacy of J-Channel score was modest for both wire and microcatheter crossing.