Abstract
Background and Objectives: The roles of final kissing balloon inflation (FKBI) in single stenting remain controversial, with no prior studies evaluating its impact on angiographic restenosis from the perspective of coronary microcirculation. This study aimed to investigate whether FKBI reduced angiographic restenosis in patients treated with single stenting in the left main (LM)-left anterior descending (LAD) after propensity score matching (PSM) to balance baseline characteristics, including the pre-procedural angiography-derived index of microcirculatory resistance (AMR). Additionally, it aimed to demonstrate the temporal changes in AMR (pre-procedure, post-procedure, and follow-up) and their impact on angiographic restenosis. Materials and Methods: AMR was calculated based on coronary angiography from a single view of the LM-left circumflex (LCX), pre- and post-procedure and during follow-up. Long-term angiographic restenosis was assessed using percent diameter stenosis (DS%). Results: A total of 197 patients underwent the simple crossover, and 70 underwent FKBI, while 61 pairs were matched after the PSM. The long-term DS% in the LM and LAD was lower in the FKBI group after the PSM. The long-term AMR demonstrated an increase in the simple crossover group but stability in the FKBI group. The long-term AMR was lower post-FKBI regardless of the PSM. The pre-procedural AMR was a positive predictor of long-term LAD angiographic restenosis in the simple crossover group, but it did not show any correlation in the FKBI group. Conclusions: After PSM involving pre-procedural AMR, FKBI could reduce long-term angiographic restenosis in the LM and LAD following left main distal bifurcation single stenting and exhibited lower long-term AMR compared to the simple crossover group. The pre-procedural AMR predicted the future LAD progression in the simple crossover group, yet FKBI seemed to nullify the association.