Choice of CTO scores to predict procedural success in clinical practice. A comparison of 4 different CTO PCI scores in a comprehensive national registry including expert and learning CTO operators

BACKGROUND: We aimed to compare the performance of the recent CASTLE score to J-CTO, CL and PROGRESS CTO scores in a comprehensive database of percutaneous coronary intervention of chronic total occlusion procedures. METHODS: Scores were calculated using raw data from 1,342 chronic total occlusion procedures included in REBECO Registry that includes learning and expert operators. Calibration, discrimination and reclassification were evaluated and compared. RESULTS: Mean score values were: CASTLE 1.60±1.10, J-CTO 2.15±1.24, PROGRESS 1.68±0.94 and CL 2.52±1.52 points. The overall percutaneous coronary intervention success rate was 77.8%. Calibration was good for CASTLE and CL, but not for J-CTO or PROGRESS scores. Discrimination: the area under the curve (AUC) of CASTLE (0.633) was significantly higher than PROGRESS (0.557) and similar to J-CTO (0.628) and CL (0.652). Reclassification: CASTLE, as assessed by integrated discrimination improvement, was superior to PROGRESS (integrated discrimination improvement +0.036, p<0.001), similar to J-CTO and slightly inferior to CL score (– 0.011, p = 0.004). Regarding net reclassification improvement, CASTLE reclassified better than PROGRESS (overall continuous net reclassification improvement 0.379, p<0.001) in roughly 20% of cases. CONCLUSION: Procedural percutaneous coronary intervention difficulty is not consistently depicted by available chronic total occlusion scores and is influenced by the characteristics of each chronic total occlusion cohort. In our study population, including expert and learning operators, the CASTLE score had slightly better overall performance along with CL score. However, we found only intermediate performance in the c-statistic predicting chronic total occlusion success among all scores.