Predictors and Impact for Side Branch Occlusion after Bioresorbable Vascular Scaffold Implantation: Insights from Multimodal Imaging and 2-Year Clinical Outcomes.

BACKGROUND: There is a lack of intravascular imaging assessment and long-term clinical follow-up regarding side branch occlusion (SBO) after bioresorbable vascular scaffold (BVS) implantation. The aim of this study was to identify independent predictors of SBO after BVS implantation and characterize its short- and long-term outcomes. METHODS: This study enrolled 444 patients undergoing BVS implantation. Quantitative coronary angiography was performed to analyze 460 lesions and 1,094 side branches (SB), with independent predictors of SBO identified through generalized linear mixed models. Virtual histology technology based on optical coherence tomography was utilized to characterize main vessel plaque morphology. All enrolled patients completed clinical follow-up at 30 days and 2 years post-procedure. RESULTS: The incidence of BVS-SBO was 4.9% (54/1,094 SBs), with independent predictors including SB diameter < 1 mm (OR = 3.999, p < 0.001), SB ostial stenosis > 50% (OR = 6.244, p < 0.001), and SB location within the obstruction segment (OR = 8.668, p < 0.001). SBO lesions showed higher relative volumes of lipid plaque (29.5% vs. 22.9%, p = 0.028) and calcified plaque (2.7% vs. 1.1%, p = 0.027) compared with non-SBO lesions. The SBO group exhibited a markedly higher incidence of perioperative myocardial infarction (33.3% vs. 10.8%, p < 0.001), although there was no significant difference in 2-year major adverse cardiovascular events (5.6% vs. 4.1%, p = 0.629) between groups. CONCLUSION: SBO after BVS implantation is associated with SB anatomical characteristics and plaque features. While SBO increases the incidence of perioperative myocardial infarction, it does not elevate long-term clinical risk.