Drug-eluting stents effectively reduce restenosis but may increase late thrombosis and delayed restenosis. Persistent polymer could be responsible. Local delivery of paclitxel from a polymer-free Yinyi stent (Dalian Yinyi biomaterial research and development co.ltd) may prevent these complications.

Inclusion Criteria:

• age 18-80 years old
• both gender
• native coronary lesion
• narrowing > 70%
• vessel size 2.5-4.0 in diameter

Exclusion Criteria:

• without informed consent,
• ST elevation myocardial infarction within 7 days,
• patient with ≤ 70% coronary narrowing at target lesion,
• left main lesion,
• multivessel narrowing need more than 3 stent implantations,
• by-pass graft,
• abnormal liver function before randomization,
• active hepatitis or muscular disease,
• impaired renal function with serum creatinine level > 3mg/dl,
• impaired left ventricular function with LVEF < 30%,
• Participate in other studies.