Background:Whether final kissing balloon (FKB) dilatation after one-stent implantation at left-main (LM) bifurcation site remains unclear.Therefore,this large sample and long-term follow-up study comparatively assessed the impact of FKB in patients with unprotected LM disease treated with one-stent strategy.Methods:Total 1528 consecutive patients underwent LM percutaneous coronary intervention in one center from January 2004 to December 2010 were enrolled; among them,790 patients treated with one drug-eluting stent crossover LM to left anterior descending (LAD) with FKB (n =230) or no FKB (n =560) were comparatively analyzed.Primary outcome was the rate of major adverse cardiovascular events,defined as a composite of death,myocardial infarction (MI) and target vessel revascularization (TVR).Results:Overall,The prevalence of true bifurcation lesions,which included Medina classification (1,1,1),(1,0,1),or (0,1,1),was similar between-groups (non-FKB:37.0％ vs.FKB:39.6％,P =0.49).At mean 4 years follow-up,rates of major adverse cardiovascular events (non-FKB:10.0％ vs.FKB:7.8％,P =0.33),death,MI and TVR were not significantly different between-groups.In multivariate propensity-matched regression analysis,FKB was not an independent predictor of adverse outcomes.Conclusions:For patients treated with one-stent crossover LM to LAD,clinical outcomes appear similar between FKB and non-FKB strategy.