Impact of Bifurcation Involvement and Location in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights from the EuroCTO Registry

Bifurcation involvement close to or within the occluded segment poses increasing difficulties for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). However, this variable is not considered in the angiography-based CTO scoring systems nor has been extensively investigated in large multicenter series. Accordingly, we analyzed a CTO-PCI registry involving 92 European centers to explore the incidence, angiographic and procedural characteristics, and outcomes specific to CTO-PCIs with bifurcation involvement. A total of 3948 procedures performed between January and November 2023 were examined (33% with bifurcation involvement). Among bifurcation lesions, 38% and 37% were located within 5mm of the proximal and distal cap, respectively, 16% within the CTO body, and in 9% of cases proximal and distal bifurcations coexisted. When compared with lesions without bifurcation involvement, CTO bifurcation lesions had higher complexity (J-CTO 2.33±1.21 vs 2.11±1.27, p<0.001) and were associated with higher use of additional devices (dual-lumen microcatheter in 27.6% vs 8.4%, p<0.001, and intravascular ultrasound in 32.2% vs 21.7%, p<0.001). Radiation dose (1544[836-2819] vs 1298.5[699.1-2386.6]mGy, p<0.001) and contrast volume (230[160-300] vs 190[130-250]ml, p<0.001) were also higher. Technical success was similar (91.5% with bifurcation involvement vs 90.4% without bifurcation involvement, p=0.271). However, the bifurcation lesions within the CTO segment (intralesion) were associated with lower technical success than the other bifurcation location subgroups (83.7% vs 93.3% proximal, 93.4% distal, and 89.0% proximal & distal, p<0.001). On multivariable analysis, the presence of an intralesion bifurcation was independently associated with technical failure (OR 2.19, 95%CI 1.52-3.16, p=0.001). In conclusion, bifurcations are present in approximately one third of CTOs undergoing PCI. PCI of CTOs with bifurcation can be achieved with high success rates except for bifurcations within the occluded segment, that were associated with higher technical failure.