Assessment of the ERCTO Score for Predicting Success in Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions in the PROGRESS-CTO Registry

BACKGROUND: The retrograde strategy is a common approach used in complex chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The ERCTO Retrograde score is a tool that aims to predict the likelihood of technical success for retrograde CTO PCI procedures by evaluating five parameters: calcification, distal opacification, proximal tortuosity, collateral connection classification, and operator volume. METHODS: We evaluated the performance of the ERCTO Retrograde score using data from 2,341 patients enrolled in the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) at 35 centers between 2013 and 2023. RESULTS: Retrograde CTO PCI was the primary crossing strategy in 871 cases (37.2%) and a secondary crossing strategy in 1,467 cases (62.8%). Technical success was achieved in 1,810 cases (77.3%). The technical success rate was higher for primary retrograde cases compared with secondary retrograde cases (79.8% vs 75.9%; P=.031). The ERCTO Retrograde score was positively associated with the likelihood of procedural success. The c -statistic of the ERCTO retrograde score was 0.636 (95% confidence intervals [CI]: 0.610 - 0.662) for all cases and 0.651 (95% CI: 0.607 - 0.695) for primary retrograde cases. CONCLUSIONS: The ERCTO Retrograde score has modest predictive capacity for technical success in retrograde CTO PCI.