Impact of Bifurcation Angle on Side Branch Occlusion in Provisional Bifurcation Percutaneous Coronary Intervention: Analysis from the PROGRESS-BIFURCATION Registry.

Limited information exists on the impact of the bifurcation angle on side branch occlusion (SBO) in provisional percutaneous coronary intervention (PCI). We examined the procedural characteristics and outcomes of 1015 bifurcation PCIs (855 patients) that were performed using the provisional technique between 2014 and 2023 from a multicenter bifurcation PCI registry (NCT05100992). The median bifurcation angle was 60° (interquartile range [IQR] 40°-80°). Patients were divided into 3 groups: narrow angle (<45°), middle angle (45-70°), and wide angle (>70°). Patients in all groups had similar baseline clinical characteristics. Lesions in the wide-angle group had larger proximal and distal main vessel and side branch diameter. Technical and procedural success and in-hospital major adverse cardiovascular events (MACE) were similar in all groups. Overall SBO was 14.6% and was more likely to be observed in the narrow angle group (22.6%) than the remaining groups (middle angle 11.7%, wide angle 12.8%, p <0.001). In multiple logistic regression analysis, wider bifurcation angle was associated with lower risk of SBO (adjusted odds ratio [aOR] per 10-degree increments: 0.88 [95% confidence interval (CI), 0.80 to 0.98; p = 0.017]). A U-shaped association was seen between bifurcation angle and SBO, where restricted cubic spline analysis demonstrated that the lowest risk of SBO was at a bifurcation angle of 100° (aOR 0.19, 95% CI 0.07 to 0.55, p = 0.002). In patients undergoing provisional stenting, narrow bifurcation angle was associated with higher SBO risk.