Influence of Isolated Side Branch Lesions on Procedural Techniques and Clinical Outcomes in Bifurcation Percutaneous Coronary Intervention

Coronary bifurcation lesions remain among the most technically demanding scenarios in percutaneous coronary intervention (PCI), with procedural success and long-term outcomes influenced by lesion complexity, vessel geometry, and side branch (SB) involvement. While significant disease in both the main vessel and SB has been extensively studied, the clinical and procedural implications of isolated SB lesions remain insufficiently characterized. The optimal interventional strategy for these lesions continues to be debated, particularly regarding the necessity of SB stenting versus conservative or provisional approaches. This study evaluates the influence of isolated SB lesions on PCI procedural techniques and subsequent clinical outcomes in patients undergoing bifurcation interventions. A comprehensive analysis was conducted using angiographic, intravascular imaging, and physiological assessment parameters, including fractional flow reserve and instantaneous wave-free ratio, to determine SB functional significance and guide treatment selection. Procedural strategies assessed included balloon angioplasty alone, drug-coated balloon therapy, and dedicated SB stenting techniques, with particular attention to procedural complexity, fluoroscopy time, contrast utilization, and periprocedural complications. Clinical outcomes were assessed across short- and intermediate-term follow-up, focusing on major adverse cardiovascular events, target lesion revascularization, SB patency, and incidence of restenosis or thrombosis. The findings suggest that physiological and imaging-guided decision-making plays a critical role in identifying SB lesions that benefit from intervention while avoiding unnecessary procedural escalation. Additionally, lesion morphology, SB vessel size, and bifurcation angle were identified as key determinants influencing procedural success and durability of revascularization. These results support a tailored, physiology-driven approach to the management of isolated SB lesions in bifurcation PCI. Incorporating advanced imaging modalities and individualized procedural planning may improve clinical outcomes, reduce procedural complexity, and optimize long-term vessel patency in this challenging subset of coronary artery disease.