Angiographic Scoring System for Predicting Successful Percutaneous Coronary Intervention of In-Stent Chronic Total Occlusion

The purpose of this study was to develop a scoring model to predict the technical success of recanalizing via antegrade approach in-stent chronic total occlusion (IS-CTO) by percutaneous coronary intervention (PCI). We retrospectively collected data from 474 patients who underwent an uneasy IS-CTO PCI via antegrade approach from January 2015 to December 2018, consecutively. We selected clinical and angiographic factors and utilized a derivation and validation cohort (4:1 sampling ratio) analysis. Factors with strong correlations with technical failure, according to multivariable analysis, were assigned 1 point, and a scoring system with a 4-point maximum was established. The model was then validated with a validation cohort. The overall procedural success rate was 77.4%. On multivariable analysis, the factors that correlated with technical failure were proximal bending (beta coefficient [ β ] = 2.142), tortuosity ( β = 2.622), stent under expansion ( β = 3.052), and poor distal landing zone ( β = 2.004). The IS-CTO score demonstrated good calibration and excellent predicting capacity in the derivation (receiver-operator characteristic [ROC] area = 0.973 and Hosmer-Lemeshow chi-squared = 5.252; p = 0.072) and validation (ROC area = 0.976 and Hosmer-Lemeshow chi-squared = 0.916; p = 0.632) cohorts. In the validation subset, the IS-CTO score demonstrated superior performance to the Japanese chronic total occlusion score (J-CTO) and PROGRESS CTO scores for predicting technical success (area under the a curve [AUC] 0.976 vs. 0.642 vs. 0.579, respectively; difference in AUC between the IS-CTO score and J-CTO score = 0.334, p < 0.01; difference in AUC between the IS-CTO score and PROGRESS score = 0.397 , p < 0.01). Our results suggest that the IS-CTO score system is a helpful tool to predict the technical success of IS-CTO PCI via antegrade approach in china. Graphical Abstract