- angiographic criteria is complex coronary lesions which includes the followings: multivessel lesions(>or=two vessels), diffuse long lesions with length>or=30mm or need two stents overlapped, small vessel lesions(reference vessel diameter<or=2.5mm estimated by investigator), bifurcation lesions need one or two stents and side branch diameter>2.0mm, chronic total occlusion lesions(>3 months), ostial target lesions(including ostial of right coronary artery,left anterior descending artery and left circumflex artery), severe calcification or angulation(location of target lesion at a >45°bend), protected and unprotected left main lesions, restenosis after bare metal stent implantation(core laboratory decision )