Occlusion patterns, strategies and procedural outcomes of percutaneous coronary intervention for in-stent chronic total occlusion

BACKGROUND: In-stent chronic total occlusion (CTO) presents various occlusion patterns, which complicate percutaneous coronary intervention (PCI). AIMS: The aim of the study was to investigate the initial outcome and strategy of PCI for in-stent CTO according to the angiographic occlusion patterns. METHODS: This study assessed 791 in-stent CTOs from the Japanese CTO-PCI Expert Registry from 2015 to 2018. They were divided into four patterns: pattern A (n=419), CTO within the stent segment; pattern B (n=196), CTO beyond the distal edge; pattern C (n=85), CTO beyond the proximal edge; and pattern D (n=69) CTO beyond both the proximal and distal edges. RESULTS: There were significant differences in the technical success rates (96.2%, 86.2%, 92.9%, and 75.4% for patterns A-D, respectively; p<0.001), guidewire crossing times (22 interquartile range: 10-46, 52 24-102, 40 20-78, and 86 45-127 min, respectively; p<0.001), and the rates of antegrade approach alone (90.9%, 61.2%, 67.1%, and 31.9%, respectively; p<0.001). CONCLUSIONS: PCI for CTO within the stent segment was associated with excellent initial outcomes with the antegrade approach. However, PCI for CTO beyond both the proximal and distal edges was associated with the poorest outcomes, even with the bidirectional approach.