Difficulty in enrolling the required number of participants has made it impractical to proceed with the trial.

Diabetic patients are prone to a diffuse and rapidly progressive form of atherosclerosis. Both clinical and angiographic outcomes following percutaneous coronary intervention (PCI) are poor in patients with DM compared with those without DM. Autopsy study has shown delayed neointimal healing with inadequate endothelialization and persistent stent surface fibrin deposition after DES implantation in DM patients. This might partially contribute to the high risk of late stent thrombosis.

YINYI Polymer-Free paclitaxel stent is a domestic new type stent with bare metal base with micro porous surface. However, limited data is available in vivo about the surface coverage after stent implantation in DM patients because of lack of sensitive imaging modalities. Optical coherence tomography (OCT) is an optical analogue of intravascular ultrasound（IVUS）that allows high-resolution tomographic intravascular imaging. Furthermore, several studies have demonstrated the feasibility of OCT to quantitatively evaluate the surface coverage and stent conditions in the follow up after PCI .

Therefore, the aim of this study was to analyze the surface coverage and late malapposition after two types of DES implantation in DM patients compared with non-DM patients by using OCT and IVUS.

Diabetic patients are prone to a diffuse and rapidly progressive form of atherosclerosis. Both clinical and angiographic outcomes following percutaneous coronary intervention (PCI) are poor in patients with DM compared with those without DM. Autopsy study has shown delayed neointimal healing with inadequate endothelialization and persistent stent surface fibrin deposition after DES implantation in DM patients. This might partially contribute to the high risk of late stent thrombosis.

YINYI Polymer-Free paclitaxel stent is a domestic new type stent with bare metal base with micro porous surface. However, limited data is available in vivo about the surface coverage after stent implantation in DM patients because of lack of sensitive imaging modalities. Optical coherence tomography (OCT) is an optical analogue of intravascular ultrasound（IVUS）that allows high-resolution tomographic intravascular imaging. Furthermore, several studies have demonstrated the feasibility of OCT to quantitatively evaluate the surface coverage and stent conditions in the follow up after PCI .

Inclusion Criteria:

General Inclusion Criteria：

1. Age : 18-75Y
2. Patients diagnosed as type 2 DM or non-DM.

Angiographic Inclusion Criteria：

1. Patients were considered eligible if they have two significant (>70%) angiographic stenosis lesions in different native coronary vessels by CAG.
2. Each target is de novo lesion that can be treated with 1-2 stents.
3. Reference vessel diameter of 2.5 to 4.0 mm.

Exclusion Criteria:

General Exclusion Criteria：

1. ST-segment elevation myocardial infarction within 7 days prior to the index procedure.
2. Life expectancy <12 months due to another medical condition.
3. Contraindication to antiplatelet therapy or a history of hypersensitivity to sirolimus and paclitaxel or structurally related compounds.
4. Creatinine level more than 2.0mg/dL or ESRD.
5. Severe hepatic dysfunction (more than 3 times normal reference values).
6. Planned surgery procedure≤12 months post-index procedure.
7. Known allergy to stainless steel.
8. Female of childbearing potential with a positive pregnancy test within 7 days before the index procedure, or lactating, or intends to become pregnant during the 12 months post index procedure.
9. Patient is not clinically appropriate for OCT evaluation in the opinion of investigator.

Angiographic Exclusion Criteria：

1. Study lesion is ostial in location (within 3.0 mm of vessel origin).
2. Study lesion involving arterial segments with highly tortuous anatomy.
3. Complex lesion morphologies (bifurcation needs two stents technique, left main lesion, chronic obstructive occlusion, severe thrombus, heavy calcification).