Objectives: The aim of this study was to investigate the long-term outcomes of intravascular ultrasound (IVUS) guidance stenting in bifurcation lesions. Background: Stenting for bifurcation lesion is still challenging and the impact of IVUS guidance on long-term outcomes has not been evaluated. Methods: We evaluated 758 patients with stenting for de novo bifurcation lesions between January 1998 and February 2006. We compared adverse outcomes for 4 years (death, stent thrombosis, and target lesion revascularization) in the overall group and in separate subgroups as stent type. The variables were adjusted by use of the multivariate Cox proportional hazard model and propensity score. Results: IVUS guidance stenting significantly reduced long-term mortality in overall group (hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.13 to 0.74, p=0.008) and drug-eluting stent group (HR 0.24; 95% CI, 0.06 to 0.86, p=0.03). In contrast, IVUS guidance did not reduce the risk of long-term mortality in patients receiving bare-metal stent (HR, 0.41; 95% CI, 0.13 to 1.26, p=0.12). There was no significant difference as guidance method in the risk of stent thrombosis (HR 0.48; 95% CI, 0.16 to 1.43, p=0.19) and target lesion revascularization (HR 1.47; 95% CI, 0.79 to 2.71, p=0.21), although a trend favoring IVUS guidance was seen for development of very late stent thrombosis (HR 0.12; 95% CI, 0.01 to 1.01, p=0.05). Conclusions: IVUS guidance stenting for bifurcation lesions significantly reduces 4 year mortality when compared with conventional angiography guidance.

Outcome	Overall group		DES group		BMS group
	Hazard ratio (95% CI)	p value	Hazard ratio (95% CI)	p value	Hazard ratio (95% CI)	p value
Unadjusted
Death	0.22 (0.10-0.50)	< 0.001	0.21 (0.06-0.72)	0.01	0.27 (0.09-0.81)	0.02
Stent thrombosis	0.45 (0.16-1.30)	0.14	0.27 (0.06-1.22)	0.09	0.78 (0.17-3.48)	0.74
TLR	1.36 (0.77-2.41)	0.29	0.94 (0.39-2.24)	0.88	2.13 (1.00-4.55)	0.05
Multivariable adjusted
Death	0.31 (0.13-0.74)	0.008	0.24 (0.06-0.86)	0.03	0.41 (0.13-1.26)	0.12
Stent thrombosis	0.48 (0.16-1.43)	0.19	0.35 (0.08-1.64)	0.18	1.09 (0.22-5.34)	0.92
TLR	1.47 (0.79-2.71)	0.21	0.92 (0.38-2.25)	0.86	2.27 (0.99-5.25)	0.05
Propensity score adjusted
Death	0.13 (0.03-0.66)	0.01	0.21 (0.06-0.73)	0.01	0.4 (0.1-1.2)	0.11
Stents thrombosis	0.30 (0.07-1.32)	0.11	0.28 (0.06-1.25)	0.10	1.0 (0.2-4.9)	0.98
TLR	0.63 (0.23-1.72)	0.36	0.90 (0.33-2.54)	0.84	1.67 (0.75-3.72)	0.21