Background Drug-eluting stents(DES)have been shown to significantly reduce clinical events and angiographic restenosis in the treatment of coronary artery disease(CAD).This study was conducted to assess the long-term efficacy and safety of the polymer-based sirolimus-eluting cobalt-chromium Firebird 2TM stents in the treatment of patients with CAD.Methods This first-in-man study using the Firebird 2TM stent is a prospective,historically-controlled multicenter clinical study,which enrolled 67 patients with CAD who were treated with the sirolimus-eluting cobalt-chromium stent(Firebird 2TM,Microport Shanghai,Firebird 2 group),compared to another 49 patients treated with a bare cobalt alloy stent(Driver,Medtronic,control group).Continued 2-year clinical follow-up was performed after getting the initial 6-month angiographic and 1-year clinical follow-up.The incidence of major adverse cardiac events(MACE)including cardiac death,reinfarction and target lesion revascularization(TLR)and stent thrombosis were compared between the two groups.Results All patients in the Firebird 2 group(100.0%)and 48 patients in the control group(98.O%)completed the 2-year clinical follow-up.At the 1-year follow-up the use of the Firebird 2 stent was highly effective,resulting in a significant 94% decrease of TLR (26.5%in the control group and 1.5%in the Firebird 2 group,P＜0.0001).A significant difference in TLR was maintained at 2-year follow-up,Firebird 2 group 1.5%and the control group 31.3%(P＜0.0001).Between 1-and 2-year post-stenting.no more TLR occurred in the Firebird 2 group compared with two cases in the control group (P＞0.05).There was a 1.5%incidence of MACE at 1-and 2-year follow-up in the Firebird 2 group,compared with 26.5% and 33.3%in the control group,respectively(all P＜0.0001).The cumulative 1-and 2-year MACE free survival rates were 98.5%in the Firebird 2 group vs 73.5%and 66.7% in the control group (log rank P＜0.0001).No case of stent thrombosis occurred during 2-year follow-up in the Firebird 2 group,compared with one case that suffered a definite stent thrombosis in the control group at 19-month post-stenting:this patient presented with unstable angina pectoris and was treated by balloon angioplasty.Conclusions Compared with the bare cobalt alloy stent,the Firebird 2TM sirolimus-eluting cobalt-chromium stent is safe and effective in treating patients with CAD.The use of this stent was associated with a sustained clinical benefit and significantly lower rate of TLR and MACE up to 2 years post-stenting.